The displacement time graph of a particle executing S.H.M. is given in figure: (sketch is schematic and not to scale)Which of the following statements is/are true for this motion?(A) The force is zero at  t=3T4(B) The acceleration is maximum at t = T(C) The speed is maximum at  t=T4(D) The P.E. is equal to K.E. of the oscillation at  t=T2