A Source Emits Sound with a Frequency of 1000 Hz

Multiple Choice

A source emits sound with a frequency of 1000 Hz.It and an observer are moving toward each other, each with a speed of 100 m/s.If the speed of sound is 340 m/s, the observer hears sound with a frequency of:

A) 290 Hz
B) 540 Hz
C) 1000 Hz
D) 1800 Hz
E) 3400 Hz