After looking at the transverse waves in the diagram you listed above, the one diagram that does represent the direction of particle X at the instant show in diagram number 3. The direction of the wave motion is up. The correct answer choice will be 3.
Since the ball was not moving before it let Aiden's hand, the formula used to calculate the acceleration is , where a is acceleration, v is velocity and t is the time. We put them in the formula and get The acceleration is 490 m/s^2