Simple Pendulum: If both the mass of a simple pendulum and its length are doubled, the period will

A$)$ increase by a factor of $2.$

B$)$ be unchanged.

C$)$ increase by a factor of $4.$

D$)$ increase by a factor of $\frac{1}{\sqrt[\phantom{2}]{2}}.$

E$)$ increase by a factor of $\sqrt[\phantom{2}]{2}.$