In my opinion, the correct answer is A. simile. You can see that in the construction "four men (...) like burglars". A simile is actually a comparison that always follows this formula: A is like B. It usually uses the conjunctions (like/as), but sometimes, in its shorter form, it doesn't even need them. We don't see a metaphor here - every word is used in its literal meaning. We don't see an irony either. As for syntax, it is not even a literary device.
