As asked, the answer might be single-minded or closed-minded.
However, there is a clarification that needs to be made. Note that B has not "pointed out" the lack of relevance, but rather has indirectly asserted it. Your question assumes B's position is correct, and (particularly in political and religious discussions) it is entirely possible that A profoundly disagrees. As to who is correct is beyond the scope of this discussion.
In any event, B's question constitutes a deflection of A's query, and from A's point of view may well constitute an evasion. In this case, A's response is an attempt to get B to stop avoiding the question. Whether the question should be avoided is another matter.