【单选题】

{{I}}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. Now listen to the conversation.{{/I}} What is the man doing

A、Calling an information center.
B．Reserving a round-trip ticket for himself.
C．Buying a one-way ticket for his wife.
D．Booking a one-way ticket via telephone.