The Figure Shows Two Point Sources of Light,A and B $\pi$

Multiple Choice

The figure shows two point sources of light,A and B.B emits light waves that are + $\pi$ radians out of phase with the waves from A.A is 3 $\lambda$ from P.B is 5 $\lambda$ from P.( $\lambda$ is the wavelength. ) The phase difference between waves arriving at P from A and B is

A) 0 rad.
B) $\pi$ rad.
C) 2 $\pi$ rad.
D) 3 $\pi$ rad.
E) 4 $\pi$ rad.