A thin uniform rod $A B$ of mass $M$ and length $L$ is hinged at one end $\mathrm{A}$ to the horizontal floor. Initially it stands vertically. It is allowed to fall freely on the floor in the vertical plane. The angular velocity of the rod when its end $B$ strikes the floor is
$\{\mathrm{A}\} \sqrt{(\mathrm{g} / \mathrm{L})}$
$\{\mathrm{B}\} \sqrt{(2 \mathrm{~g} / \mathrm{L})}$
$\{C\} \sqrt{(3 g / L)}$
$\{\mathrm{D}\} 2 \sqrt{(\mathrm{g} / \mathrm{L})}$