The single choice field is not being deselected

Good afternoon, 

On Page 4 of my form I have many design options for magazine ads.  I am specifically having trouble deselecting an option if selected in error.  This leads to double selections.  Can you tell me why an option cannot be deselected, usually by clicking on the same selection again...? 

In the upload below, under Regional Club Ad, you will see that B&W One Page ...($160.00), was inadvertently selected and my advertiser cannot deselect it.

The single choice fields are not deselectable. You may try adding a "None" option or using a dropdown as a workaround. 
Or