Answer: The semicolon is used correctly in sentence D. Joe watered the garden; however, the plants did not grow.
Step-by-step explanation: A semicolon is a punctuation mark mainly used to join two independent clauses. When using a semicolon, conjunctions should not be added. Moreover, a semicolon is used in a sentence when there is a conjunctive adverb connecting two independent clauses. Therefore, the sentence that uses the semicolon correctly is D. ("Joe watered the garden; however, the plants did not grow") since the semicolon has been used before a conjunctive adverb ("however") that is connecting two independent clauses.