A particle starts from a point `P` at a distance of `A//2` from the mean position `O &` travels towards left as shown in the figure. If the time period of `SHM`, executed about `O` is `T` and amplitude `A` then the equation of motion of particle is :
A. `X=A sin ((2pi)/(T)t+(pi)/(6))`
B. `X=A sin((2pi)/(T)t+(5pi)/(6))`
C. `X=A cos((2pi)/(T)t+(pi)/(6))`
D. `X=A cos ((2pi)/(T)t+(pi)/(3))`