An Observer Stands 3 M from Speaker a and 4 $\frac { \pi } { 2 }$

Multiple Choice

An observer stands 3 m from speaker A and 4 m from speaker B.Both speakers,oscillating in phase,produce 170 Hz waves.The speed of sound in air is 340 m/s.What is the phase difference (in radians) between the waves from A and B at the observer's location,point P?

A) 0
B) $\frac { \pi } { 2 }$
C) $\pi$
D) 2 $\pi$
E) 4 $\pi$