The sentence that represents a paradox is:
B. This is a genuine imitation of that designer watch.
Explanation:
A paradox is a statement that may seem contradictory or absurd but may be true in reality. In this sentence, the idea of a "genuine imitation" presents a contradiction because something genuine is original, whereas an imitation is a copy of something else. Therefore, the sentence creates a paradox by combining these two contradictory terms.