The answer is B. The introductory text in the sentence cannot stand alone. Thus, the introductory text in the sentence cannot stand alone explains best why the colon after "including” should be removed.
B. The introductory text in the sentence cannot stand alone.
A colon can only be used when the text before the colon can stand alone as a complete sentence. The text before the colon is "I need to stop at several places, including". Including causes this sentence to be a fragment and therefore the colon is not grammatically correct. Options A, B, and C are all incorrect statements about colons.
