An Equation That Gives the Particle Displacement for a Medium

Multiple Choice

An equation that gives the particle displacement for a medium in which there is a simple harmonic traveling wave is where x and y are in centimeters and t is in seconds.At t = 2 s the speed of a particle at the location x = 4 cm is

A) 0
B) 2 cm/s
C) 4 cm/s
D) 6 cm/s
E) 8 cm/s