Correct Answer - C
Let diaplacement equation of particle excuting SHM is
`y= a sin omega t`
Therefore, `(a)/(2)= a sin omega t`
or `sin omega t=(1)/(2)= (sin)(pi)/(6)`
or `omega t= (pi)/(6)`
or `t=(pi)/(6 omega)`
or `t=(pi)/(6(2pi/T)) (as omega= (2pi)/(T))`
or `t=(T)/(12)`
Hence, the particle travels half to the amplitude from the equilibrium in `(T)/(12)s`.