I'm trying to customise a Side by Side block to limit the number of responses a person can make

I am trying to create a block of questions in which participants can only select 2 options out of 6. Unfortunately the way the block is set up at the moment means that it's forcing me to select 3 responses out of 6. I was wondering if anyone might be able to recommend some work arounds.

Could I potentially create a java script to make it impossible to select three responses? I have attached two images. One image is showing what I'm trying to achieve (2 out 6 selections)

The other image is showing what the system does (3 out of 6). There seems no way to prevent the third selection.

I was wondering if anyone might have some suggestions of a work around?

!
!