QuickCheck $15\mathrm{.}13$

On Planet X$,$ a ball on a massless, rigid rod oscillates as a simple pendulum with a period of $2\mathrm{.}0$ s $.$ If the pendulum is taken to the moon of Planet X$,$ where the free$-$fall acceleration $\backslash ($ g $\backslash )$ is half as big, the period will be

A$.1\mathrm{.}0$ s

B$.1\mathrm{.}4$ s

$\backslash ($ T$=2\backslash$pi $\backslash$sqrt$\{\backslash$frac$\{$L$\}\{$g$\}\}\backslash )$

C$.2\mathrm{.}0$ s

D$.2\mathrm{.}8$ s

E$.4\mathrm{.}0$ s