An electric lift is moving downwards with a acceleration of $\frac{g}{3}$ . The vertical force between a passenger in the lift and its floor equal to
(a) $\frac{2}{3}$ of the passenger’s weight
(b)$\frac{3}{4}$ of the passenger’s weight
(c) passenger’s weight
(d) $\frac{4}{3}$ of the passenger’s weight