Hide List Box if

I have two list boxes:  Environment and Services.

In the "Environment" list box, I have P, N, S as options. 

I would like the "services" list box to be disabled if they select S as an option.  Is that possible?

If not, do you have any advice as to what I could do instead of using a list box for the environments?  It must be possible to multi-select so I have considered checkboxes, but I am unsure if a calculation can be used on a checkbox.  Please help.  Thank you so much for any assistance.