问题补充：
－?
－Yes, please. I want a basketball.
A. What can I do for you
B. Excuse me
C. Can you help me
D. Can I help you
答案：
A. What can I do for you
B. Excuse me
C. Can you help me
(答案→)D. Can I help you
解析：What can I do for you能为您做点什么；Excuse me打扰了；Can you help me 你能帮助我吗？Can I help you能为您帮什么忙吗？根据下文，是的，我想要一个篮球。可知选D最符合语境。
