A particle is executing Simple Harmonic Motion of time period $$T$$ in a straight line. Starting from rest, it travels a distance 'a' in the first second and distance 'b' in the next second travelling in the same direction. The amplitude of SHM is

A

$$\frac{2a^2}{3a - b}$$

B

$$\frac{3ab}{2a - b}$$

C

$$\frac{2a^2}{3a - 2b}$$

D

none of these