A block performs simple harmonic motion with equilibrium point x = 0. Graph of acceleration of the block as a function of time is shown. Which of the following statement is correct about the block?
(A) speed is maximum at t= 3s.
(B) displacement from equilibrium is maximum at t = 4s.
(C) speed is maximum at t= 4s.
(D) speed is minimum at t= 2s
