Good question - this is a great example of how the authors of the GMAT can try to obscure the conclusion of the argument.
The conclusion is some kind of opinion or call for action based upon fact. Here, the author leads by saying "although some people claim that X is true, it is not." That's the author's opinion - "it is not" - and we can derive that by looking at that language that signals transition:
"Claim" is a conclusion term, and "Although" is a transition term, so we know that the first sentence is designed to transition away from one conclusion and present an alternative:
"It is not inconsistent to support freedom of speech and also support limitations on the amount of TV violence."
Our job, now, is to strengthen that argument, and choice B shows a clear reason why it is not inconsistent - you can support something while also realizing that it may not be the overwhelming top priority, as other interests may take more precedence.
Note that, as you probably anticipated, the conclusion is key on Strengthen problems. Popular wrong answers like A and D talk more about whether or not LEGISLATION is justified, whereas the conclusion is specific to whether or not the belief is inconsistent. The conclusion does not propose legislation...it merely states that the two beliefs are not inconsistent, which makes A, D, and other choices tempting, but definitely incorrect.