The sentence with a pronoun error is the following one: An apprentice can learn how to do a trade from their master. The subject of the sentence, "An apprentice" is singular and should be matched with a singular pronoun--"his" or "her" instead of "their." The sentence should read, "An apprentice can learn how to do a trade from his master."
The <span>sentence has an incorrect shift in pronoun-antecedent agreement is letter (</span>D) An apprentice can learn how to do a trade from their master. The subject of the sentence is "an apprentice." The apprentice can either be a girl or a boy. As usual, by default man has higher hierarchy over woman. The pronoun should be used is not 'their' but 'his'.
The inclusion of reputable sources and specific facts would best strengthen the author's main argument because it would offer factual proof instead of just the author's opinion on the matter.