单项选择题

Questions 4 to 6 are based on the following conversation. At the end of the conversation, you will be given 15 seconds to answer the questions.
According to the conversation, what upsets the man

A.He doesn’t know what color to choose.
B.He has a broken rucksack.
C.The gift he wants is out of stock.
D.He doesn’t know what gift will be useful.