While Standing at a Crosswalk,you Hear a Frequency of 590

While standing at a crosswalk,you hear a frequency of 590 Hz from an approaching police car.After the police car passes,its frequency is 440Hz.What is the speed of the police car? (speed of sound = 340 m/s)

A) 24.8 m/s
B) 38.3 m/s
C) 44.7 m/s
D) 49.5 m/s
E) ​148.7 m/s