For the following questions, statement as well as the reason(s) are given. Each questions has four options. Select the correct option.
(a) Statement $-1$ is true, statement $-2$ is true; statement $-2$ is the correct explanation of statement $-1$
(b) Statement $-1$ is true, statement $-2$ is true but statement $-2$ is not the correct explanation of statement $-1$
(c) Statement $-1$ is true, statement $-2$ is false
(d) Statement $-1$ is false, statement $-2$ is true
(A) a
(B) $b$
(C) $\mathrm{c}$
(D) $\mathrm{d}$
Statement $-1:$ Periodic time of a simple pendulum is independent of the mass of the bob. Statement $-2:$ The restoring force does not depend on the mass of the bob.
(A) a
(B) $b$
(C) $\mathrm{c}$
(D) $\mathrm{d}$