The period of a simple pendulum measured inside a stationary lift is found to be T. If the lift starts accelerating upwards with acceleration of g/3 then the time period of the pendulum is

(a) $\frac{\mathrm{T}}{\sqrt{3}}$

(b) $\frac{\mathrm{T}}{3}$

(c) $\frac{\sqrt{3}}{2}\mathrm{T}$

(d) $\sqrt{3}\mathrm{T}$