Why is answer choice D wrong?

I chose answer choice D because I thought that "a university should not be entitled to patent the inventions of its faculty members" was he main conclusion and "clearly, suppressing information concerning such discoveries is incompatible with the university's obligation to promote the free flow of ideas" was the subsidiary conclusion. I applied the "why test" and it makes sense: "why shouldn't universities be entitled to patent the inventions of its faculty members? Because suppressing information concerning such discoveries is incompatible with the university's obligation to promote the free flow of ideas." I am not understanding why that is wrong. Can you explain this to me in more detail? Thank you!