Замена значений QLabel и QRadiobutton с использованием файла .json

Как вариант:

main.py:

import sys
import json
from PyQt5.Qt import *


class Example(QWidget):
    def __init__(self):
        super().__init__()
        
        with open('data.json', encoding='UTF-8') as f:
            data = json.load(f)
        self.question = (data['question'])
        self.options = (data['options'])
        self.answer = (data['answer'])
        
        self.data_size = len(self.question)
        self.q_no = 0
        self.correct = 0
        self.setObjectName('example')
        
        self.title = QLabel("Тест закинуть в программу", 
            objectName='title', alignment=Qt.AlignCenter)
        
        self.quit_button = QPushButton("Quit", objectName='quit_button')
        self.quit_button.clicked.connect(self.close)
            
        self.label_q_no = QLabel(
            self.question[self.q_no], 
            alignment=Qt.AlignCenter,
            objectName='label_q_no'
        )
     
        self.layout = QGridLayout(self)
        self.layout.addWidget(self.title, 0, 0, 1, 3,  alignment=Qt.AlignTop)
        self.layout.addWidget(self.quit_button, 1, 2,  
            alignment=Qt.AlignRight|Qt.AlignTop)
        self.layout.setRowStretch(2, 1)
        self.layout.addWidget(self.label_q_no, 3, 0, 1, 3)

        self.radiobuttons = {}
        list_rb = [] 
        self.radiobutton_1 = QRadioButton(self.options[self.q_no][0])
        self.layout.addWidget(self.radiobutton_1, 4, 0, 1, 3)
        list_rb.append(self.radiobutton_1)
        self.radiobutton_2 = QRadioButton(self.options[self.q_no][1])
        self.layout.addWidget(self.radiobutton_2, 5, 0, 1, 3)
        list_rb.append(self.radiobutton_2)
        self.radiobutton_3 = QRadioButton(self.options[self.q_no][2])
        self.layout.addWidget(self.radiobutton_3, 6, 0, 1, 3)
        list_rb.append(self.radiobutton_3)        
        self.radiobutton_4 = QRadioButton(self.options[self.q_no][3])
        self.layout.addWidget(self.radiobutton_4, 7, 0, 1, 3)
        list_rb.append(self.radiobutton_4)        
        self.radiobuttons[self.q_no] = list_rb
        self.radiobutton_5 = QRadioButton()
        
        self._group = QButtonGroup(self)
        self._group.addButton(self.radiobutton_1, 0)
        self._group.addButton(self.radiobutton_2, 1)
        self._group.addButton(self.radiobutton_3, 2)
        self._group.addButton(self.radiobutton_4, 3)
        self._group.addButton(self.radiobutton_5, 4)
        
        self.layout.setRowStretch(8, 1)
        self.next_button = QPushButton("Next", objectName='next_button')
        self.next_button.clicked.connect(self.next_btn) 
        self.layout.addWidget(self.next_button, 9, 1,  
            alignment=Qt.AlignCenter) 
        self.layout.setSpacing(0)

    def next_btn(self):        
        correct_answer = self.answer[self.q_no]
        rb = self.radiobuttons[self.q_no][correct_answer]
        if rb.isChecked():
            self.correct += 1
        
        self.q_no += 1
        if self.q_no >= self.data_size:
            self.next_button.setEnabled(False)
            text = f'''<br>Score&nbsp;&nbsp;: {int(self.correct / self.data_size * 100)}%<br>
Correct&nbsp;: {self.correct}&nbsp;&nbsp;<br>
Wrong&nbsp;&nbsp;: {self.data_size - self.correct}&nbsp;&nbsp;'''
            msg = QMessageBox.information(
                self, 
                'Результат', 
                f"<p style='color: white; text-align: center; \
                font: 15pt \"Consolas\" Bold'>{text}</p>",
            )
            return
        
        self.label_q_no.setText(self.question[self.q_no]) 
        list_rb = []
        self.radiobutton_5.setChecked(True)
        self.radiobutton_1.setText(self.options[self.q_no][0]) 
        list_rb.append(self.radiobutton_1)
        self.radiobutton_2.setText(self.options[self.q_no][1]) 
        list_rb.append(self.radiobutton_2)
        self.radiobutton_3.setText(self.options[self.q_no][2]) 
        list_rb.append(self.radiobutton_3)
        self.radiobutton_4.setText(self.options[self.q_no][3]) 
        list_rb.append(self.radiobutton_4)
        self.radiobuttons[self.q_no] = list_rb
        
        
QSS = '''
#example {
    background-color: #F0E68C;
}
#title {
    background-color: green;
    color: white;
    font: 25pt "ariel" bold;
    max-height: 50px;
}
#label_q_no {
    background-color: #F0E68C;
    color: #000080;
    font: 17pt "ariel" bold;
}
#quit_button {
    background-color: black;
    color: white;
    font: 16pt "ariel" bold;
    min-height: 30px;
    min-width: 70px;
    margin: 10px 0px;
}
#next_button {
    background-color: blue;
    color: white;
    font: 16pt "ariel" bold;
    min-width: 100px;
    min-height: 30px;
    margin-top: 10px;
}
QRadioButton {
    background-color: #F0E68C;
    color: #000;
    font: 15pt "ariel" bold;
    max-height: 50px;
    margin-top: 10px;
    margin-left: 20px;
}
QMessageBox {
    background: black;
    messagebox-information-icon: url(./images/Close.png);
}
QMessageBox QPushButton {
    padding: 2px;
    border-radius: 5px;
    background: white;
}
QMessageBox QPushButton:hover {
    background: darkCyan;
}
QDialogButtonBox {
    dialogbuttonbox-buttons-have-icons: 1;
    dialog-ok-icon: url(./images/Ok.png);
}
'''


if __name__ == '__main__':
    app = QApplication(sys.argv)
    app.setStyleSheet(QSS)
    w = Example()
    w.resize(500, 500)
    w.show()
    sys.exit(app.exec_())

data.json:

{
  "question": [
    "Q1. Тут вопрос 1?",
    "Q2. Тут вопрос 2?",
    "Q3. Тут вопрос 3?",
    "Q4. Тут вопрос 4?"
  ],
  "answer": [
    0,
    1,
    2,
    3
  ],
  "options": [
    ["Ответ правильный1",
      "Не ответ",
      "Не ответ",
      "Не ответ"
    ],
    ["Не ответ",
      "Ответ правильный2",
      "Не ответ",
      "Не ответ"
    ],
    ["Не ответ",
      "Не ответ",
      "Ответ правильный3",
      "Не ответ"
    ],
    ["Не ответ",
      "Не ответ",
      "Не ответ",
      "Ответ правильный4"
    ]
  ]
}