In the journal article by Shirk et al$.(2017),$ the authors evaluated whether lands enrolled in the Conservation Reserve Program $($CRP$)$ contributed to the occurrence of greater sage$-$grouse by providing suitable habitat. What were their primary conclusions?

CRP was not as important as the authors predicted

The authors couldn't say anything about suitable habitat because they didn't have any data on demographic performance; they only had data on occurrences of grouse

Without CRP there would be relatively large decreases in suitable sage$-$grouse habitat

a and b$,$ but not c