A circular disc has a tiny hole in it, at a distance z from its center. Its mass is M and radius R (R > z). A horizontal shaft is passed through the hole and held fixed so that the disc can freely swing in the vertical plane. For small disturbance, the disc performs SHM whose time period is the minimum for z =
(A) R/2
(B) R/3
(C) R/√2
(D) R/√3
