What is the motion of the particles in this kind of wave?

a. the particles will move up and down over large areas.
b. the particles will move up and down over small areas.
c. the particles will move side to side over small areas.
d. the particles will move side to side over large areas.

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?