I had a hard time deciding between B and C, but I picked B. For B, the inconsistency is that they defended academic restrictions for the US, but argued against those restrictions enacted by the Soviet gov. Author wants them to explain the differences in reasoning, if there are any.
For C, the general claim could be either, with the alleged exception being the one opposing the claim. I see now how there is not enough evidence to establish that this would be a "general" claim. But would you please explain further how I should go about eliminating this as a contender?