tableviewcell changing the images while scrolling - swift

Question

I have four button inside a tableview cell and each of the button has a unique as 0,1,2 and 3 respectively.
These four buttons and linked to a single button action method.
The code inside tableviewcell is as follows:
#IBOutlet weak var questionLbl: UILabel!
#IBOutlet weak var q1: UIButton!
#IBOutlet weak var q2: UIButton!
#IBOutlet weak var q3: UIButton!
#IBOutlet weak var q4: UIButton!
typealias emptyButtonClosure = (String,Int) -> ()
var buttonTapped:emptyButtonClosure?
#IBAction func btnClicked(sender:UIButton){
let buttonArray = [q1,q2,q3,q4]
for button in buttonArray {
if sender.tag == button!.tag{
button!.isSelected = true;
if let buttonTapped = buttonTapped{
buttonTapped(sender.titleLabel!.text!,sender.tag)
}
if let image = UIImage(named: "checked-radio") {
button!.setImage(image, for: .normal)
}
else
{
let image1 = UIImage(named: "unchecked-radio")
button!.setImage(image1, for: .normal)
}
}else{
button!.isSelected = false;
if let image = UIImage(named: "unchecked-radio") {
button!.setImage(image, for: .normal)
}
else
{
let image1 = UIImage(named: "checked-radio")
button!.setImage(image1, for: .normal)
}
}
}
}
These buttons are grouped into single array called as buttonarray because these buttons are radio buttons and only single selection is allowed.
Now the issue is,the value is fetched correctly for each cell in the tableview.But when the tableview is scrolled,the image position keeps changing.The code inside tableview is as follows:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "questioncell", for: indexPath) as! ChildQuestionCell
cell.questionLbl.text = self.listData?.nanniBookingDetails.questionsData[indexPath.row].question
cell.q1.setTitle(self.listData?.nanniBookingDetails.questionsData[indexPath.row].option1, for: .normal)
cell.q2.setTitle(self.listData?.nanniBookingDetails.questionsData[indexPath.row].option2, for: .normal)
cell.q3.setTitle(self.listData?.nanniBookingDetails.questionsData[indexPath.row].option3, for: .normal)
cell.q4.setTitle(self.listData?.nanniBookingDetails.questionsData[indexPath.row].option4, for: .normal)
cell.buttonTapped = { value,index in
print("button selected is",value,index)
self.answers.append(value)
}
return cell
}
How to retain the image position even when it is scrolled.Like the image selected for 1st row should not be shown in 3rd or 4th row.It should remain only in 1st row.
Please let me know how to solve this?