问题补充：
--- ?
--- They’re fine, thank you.
A. How are you
B. Who are you
C. What are they
D. How are your mother and father
答案：
A. How are you
B. Who are you
C. What are they
(答案→)D. How are your mother and father
解析：根据回答They’re fine, thank you.they是第三人称复数，所以问句中应该问they或者your mother and father也可以,故选CD，C. What are they意思是他们是干什么工作的？与回答“他们很好，谢谢你”不符合，D. How are your mother and father意思是你父母怎么样？故选D。
