An argument might also use something that seems like a synonym but isn't. for example, an argument might talk about art. One of the answer choices might talk about a museum. Museum do contain art, so that might be okay, but it might not-you need to check whether museums are actually relevant or whether the answer is just trying to get you to think so because museums do have something to do with art. Synonyms are okay if they do actually match the overall argument, but they can also be used as traps.