No wonder you had trouble
you really overthought the question stem! Its asks which claim the author cites. That just means which of the answer choices is mentioned in the passage. It's a must be true.
Also, to clarify, it doesn't matter what the author's opinion is, whether he or she agrees or disagrees with the claim. "Cites" just means "refers to".
As far as avoiding this confusion on future questions, most question stems will fit easily within one of the question types you will learn during your preparation. It's possible to see an unfamiliar question type, but first consider whether its one of the usual ones in disguise.
Thanks for the question!