This question gave me a lot of trouble with respect to choice C.
The passage states that "nunits came closer to founding a truly national black theater (X) than anyone else" has a connotation or inference that they attempted and came close but didn't really found X. So it seems a leap to say that it's same as "nunits founded perhaps what was X", which has an opposite connotation which is that they likely founded X.
It doesn't appear that there is consensus among experts on whether these two statements are same in meaning or have opposite connotation. I see why other choices are no good, but MP questions have such choices that can be eliminated per lsac standards if the two statements above don't have exactly the same meaning.
Also Line7-8 say that the nunits were "until recently, little studied". It means that they were not studied much until recently. It doesn't mean that they are "now being studied or recognized" like the choice C says. This again would disqualify C from being a correct answer.
Can someone who can see these issues explain them?