Which kind of disturbance is created by moving a spring toy up and down? perpedicular to the wave motion

in the same direction as the wave motion

in a circular motion

parallel to the wave motion

This is basically Simple Harmonic Motion - where the wave disturbance is in the same direction as the wave direction.

That describes (B).

note that y = A cos ω t          where the disturbance is y and ω the the angular frequency and is in the same direction as the disturbance y

This seems the make (D) a satisfactory answer

The projection of the disturbance y is perpendicular (sinusoidal) to the time axis, but the disturbance is still in the same direction as the wave motion

i think the answer is a, hope this : )