Physical periodic harmonic motion in grade one of senior high school For a spring oscillator, the velocity at t is V, the velocity at t is V, and the direction is the same A. It could be more than a quarter of a cycle B. It could be less than a quarter of a cycle C. It must be less than half a period D. Probably equal to half a cycle Please explain the solution carefully, thank you

Physical periodic harmonic motion in grade one of senior high school For a spring oscillator, the velocity at t is V, the velocity at t is V, and the direction is the same A. It could be more than a quarter of a cycle B. It could be less than a quarter of a cycle C. It must be less than half a period D. Probably equal to half a cycle Please explain the solution carefully, thank you

The speed is the largest in the middle and the slowest on both sides
A B D