Refer to Exhibit 18-1 Below $\pi$ )
B)2 $\pi$
C)3 $\pi$
D)4

Multiple Choice

Refer to Exhibit 18-1 below.Exhibit 18-1 The figure below shows wave crests after a stone is thrown into a pond. The phase difference in radians between points A and D is:

A) ( $\pi$ .)
B) 2 $\pi$ .
C) 3 $\pi$ .
D) 4 $\pi$ .
E) 5 $\pi$ .