单项选择题

Professor Smith teaches English in our college. He has a lovely car and drives to work every morning. Last Tuesday, however, there was something wrong with the car, so Professor Smith had to come to school by bus. He left home 40 minutes earlier than usual and arrived at school half an hour late. Poor Professor! How does Professor Smith come to college every morning

A. By taxi.
B. By bus.
C. By car.