This question is about Russia's chemical weapons in general. However, its highest-rated answer specifically talks about the Novichok nerve agent, even though that is not mentioned at all by the asker. (It is entirely possible, in fact almost certain, that the question was precipitated by the ongoing incident allegedly caused by Noviochk, but the person asking it chose not to bring that up.)
In my opinion, that makes the answer off-topic, and hence irrelevant/invalid. However I am not sure what the procedure is (if any) for dealing with answers that don't actually answer the question at hand, on this SE site.