Final answer:
The nurse should ask the client to describe the frequency and severity of their acid reflux symptoms in order to gather important information about their GERD condition.
Step-by-step explanation:
The best example of relevant questioning by the nurse in this scenario would be option A, "Can you describe the frequency and severity of your acid reflux symptoms?" This question directly addresses the client's history and experience with GERD, which is the relevant topic of the interview. By asking about the frequency and severity of symptoms, the nurse can gather important information to assess the client's condition and develop an appropriate care plan.