You Are Driving Along a Highway at 35

Multiple Choice

You are driving along a highway at 35.0 m/s when you hear the siren of a police car approaching you from behind and you perceive the frequency as 1340 Hz. You are relieved that he is in pursuit of a different speeder when he continues past you, but now you perceive the frequency as 1300 Hz. What is the speed of the police car? The speed of sound in air is 343 m/s.

A) 38.4 m/s
B) 30 m/s
C) 39.2 m/s
D) 40.1 m/s
E) 41.7 m/s