$A$ simple pendulum of length $L$ swings in a vertical plane. The tension in the string when it makes an angle $\theta$ with the vertical and the bob of mass $m$ moves with a speed $v$ is (where $g$ is the gravitational acceleration):

• A
  $m v^{2} / L$
• B
  $m g \cos \theta + m v^{2} / L$
• C
  $m g \cos \theta - m v^{2} / L$
• D
  $m g \cos \theta$