A Wave Is Represented By $y ( x , t ) = - A \cos ( \omega t - k x )$

Multiple Choice

A wave is represented by $y ( x , t ) = - A \cos ( \omega t - k x )$ . The direction the wave moves in is

A) the positive x direction.
B) the negative x direction.
C) the positive y direction.
D) the negative y direction.
E) none of the above.