Mark Twain told the friend he couldn't buy a ticket for him because ______.

A．he wanted his friend to know he had bought a ticket for him
B．he wanted to make himself heard by everyone in the compartment
C．the conductor was standing far away from him
D．the conductor had some trouble in hearing

A．the money Mark Twain's friend lost
B．the money needed to buy a ticket
C．something with which one can enter the train without a ticket
D．the money which Mark Twain borrowed from the friend