How to make Columns Exclusive in Side-By-Side Questions?

Hi everyone,
I've developed a survey that looks at the connections between members of two groups in New Zealand.
I have a side by side question (see below)
that asks to rate the stability and strength of the relationship, giving the option of selecting NA if not applicable or No relationship if there's no relationship. "No relationship" and "not applicable" should be exclusive: If there is no relationship then it can't be strong or stable. How do I do that? 
I've tried some options but they didn't work. Any help would be much appreciated!
Thanks,
Lucia