You’ll have to write about your opinion on this matter. “Trigger warnings” are warnings to alert and audience of content that could brush on a particularly upsetting subject for them and in some cases cause them to relive any experienced trauma
A simile requires "like" or "as" and metaphors require something to be called something it is not (e.g "Time is money"), finally, alliteration is the usage of repeating letters (e.g Bart Baker beat the baseball) so through the process of elimination, it is most likely assonance.
