Radio Buttons that make an image display and hide

I am using Radio Buttons to make a certain image appear when the answer is correct. In case the answer is wrong, another image will appear.

The problem is that I need to consider the possibility that the user changes his mind and chooses another radio button after he has made a fisrt choice. 

As a result of the user making a second choice, I have now two images being shown every time this happens.

So, I need to insert a command that hides the image as soon as the user changes his mind and his first option is deselected. Can you help me, please? Thanks a lot in advance.