A Wave on a Stretched String Is Reflected from a Fixed

Multiple Choice

A wave on a stretched string is reflected from a fixed end P of the string.The phase difference, at P, between the incident and reflected waves is:

A) "0 rad"
B) " $\pi$ rad"
C) " $\pi$ /2 rad"
D) "depends on the velocity of the wave"
E) "depends on the frequency of the wave"