Choose the One Alternative That Best Completes the Statement or Answers

Choose the one alternative that best completes the statement or answers the question.
-A small frictionless cart, attached to the wall by a spring, is pulled 10 cm back from its rest position and released at time t = 0 to roll back and forth for 4 sec. Its position at time t is . What is the cart's maximum speed? When is the cart moving that fast? What is the magnitude of of the acceleration then?

A) $\pi$ $\approx$ 3.14 cm/sec; t = 0.5 sec, 1.5 sec, 2.5 sec, 3.5 sec; acceleration is 0 cm/
B) 10 $\pi$ $\approx$ 31.42 cm/sec; t = 0 sec, 1 sec, 2 sec, 3 sec; acceleration is 0 cm/
C) 10 $\pi$ $\approx$ 31.42 cm/sec; t = 0.5 sec, 2.5 sec; acceleration is 1 cm/
D) 10 $\pi$ $\approx$ 31.42 cm/sec; t = 0.5 sec, 1.5 sec, 2.5 sec, 3.5 sec; acceleration is 0 cm/