A mass is attached to a spring. When is the KE at its maximum?

Question

a) at equlibrium

b) at the highest point

c) at the lowest point

d) after the spring has performed many oscillations and returned to equilibrium

I'm not sure, since none of the choices imply that the spring is moving, which is the only time when there would be kinetic energy...

Thank you!

Answer 1

I think they want a)
That is where the forces add to zero and therefore the potential energy is minimum and the ke is maximum.
As you can see from answer d), their phrasing of the question stinks. Should have said, passing through force equilibrium point.

Answer 2

Thank you!