Which sentence is a paradox? a. the comedian was seriously funny. b. this is a genuine imitation of that designer watch. c. a small crowd gathered to watch the concert. d. nobody goes to that restaurant because it is usually crowded. e. do you have the original copies we asked for?

A paradox is a sentence that is self-contradictory, meaning that it states two things that are mutually exclusive. So, the correct answer here is D. Nobody goes to that restaurant because it is usually crowded. The paradox here is how can this restaurant be crowded if nobody ever goes there? These two premises exclude each other and make the whole sentence paradoxical.