A Ball Vibrates Back and Forth from the Free End

Multiple Choice

A ball vibrates back and forth from the free end of an ideal spring having a spring constant of 20 N/m.If the amplitude of this motion is 0.30 m,what is the kinetic energy of the ball when it is 0.30 m from its equilibrium position?

A) 0.00 J
B) 0.22 J
C) 0.45 J
D) 0.90 J
E) 1.4 J