If t2-t1 = t / 4, then the distance between two points AB may be a.0 B. equal to a C. greater than a D. less than a

If t2-t1 = t / 4, then the distance between two points AB may be a.0 B. equal to a C. greater than a D. less than a

ABCD is right
For example, if you move from the position of x = 2 / 2 root 2a to the maximum displacement, and then return to this position (that is, AB coincides), the time is t / 4, and the distance between AB is 0 (this is the case of the minimum distance). If you move from this position to the equilibrium position, the time is t / 4 when you move to the position of x = - 2 / 2 root 2A, If the starting point deviates a little from this position, then the distance of AB will be slightly larger than 0, that is, less than a,
If the motion starts from the equilibrium position or from the maximum displacement, the time of T / 4 just moves a distance of A
(always, moving T / 4 near the equilibrium position will go farther, moving T / 4 at both ends will go closer, the shortest "distance" is ab = 0, at this time, the distance S = (2-root 2) a)