The graph below shows a snapshot of a wave on a string which is traveling to the right. Imagine a bit of paint on the string at point P.

At the instant shown, the velocity v (along the y-axis) of the point P on the string and the acceleration a of that point have signs...

PINK: The velocity v > 0 and acceleration a < 0

GREEN: v < 0 and a > 0

YELLOW: v > 0 and a > 0

BLUE: v < 0 and a < 0