A simple pendulum consisting of a ball of mass m tied to a thread of length l is made to swing on a circular arc of angle $\mathrm{\theta }$  in a vertical plane. At the end of this arc, another ball of mass m is placed at rest. The momentum transferred to this ball at rest by the swinging ball is 

• A

  Zero

• B

  $\mathrm{m\theta }\sqrt{\frac{\mathrm{g}}{\mathrm{l}}}$

• C

  $\frac{\mathrm{m\theta }}{\mathrm{l}}\sqrt{\frac{\mathrm{l}}{\mathrm{g}}}$

• D

  $\frac{\mathrm{m}}{\mathrm{l}}2\mathrm{\pi }\sqrt{\frac{\mathrm{l}}{\mathrm{g}}}$