What Is the Period of a Wave Described by the Following

Multiple Choice

What is the period of a wave described by the following function: y(x,t) = (2.00 m) cos[(3.00 m^-1) x + (5.00 s^-1) t]

A) 0.333 s
B) 0.200 s
C) 5.00 s
D) 1.26 s
E) 2.09 s