问题补充：
---?
---Yes, please.
A. How are you
B. Can I help you
C. What can you do for me
D. Nice to meet you
答案：
A. How are you
(答案→)B. Can I help you
C. What can you do for me
D. Nice to meet you
解析：根据情景对话中的内容要求，答案B符合题意，一般为售货员对于顾客说的，然后顾客有需要的话，就用Yes， please。故选B
