Final answer:
The sentence with an error in pronoun-antecedent agreement is b) A good leader is someone who can inspire the people who follow them, where 'them' should be 'him or her'.
Step-by-step explanation:
The sentence that contains an ERROR in pronoun-antecedent agreement is: b) A good leader is someone who can inspire the people who follow them. This sentence has a singular noun leader as the antecedent, so it should be matched with a singular pronoun. The proper pronoun agreement would be 'him or her' instead of the plural 'them' Correct pronoun-antecedent agreement is essential for clarity in writing. If a singular antecedent is present, the pronoun also must be singular. If the antecedent would prefer not to specify gender or if the gender is unknown, 'they' can sometimes be used as a singular pronoun in informal contexts, but 'him or her' or rephrasing is preferred in formal writing.