$P -$ Assertion: The inner membrane of the mitochondria forms a number of infoldings called cristae,which contain $F_1$ particles.
$Q -$ Reason: Cristae contain the components necessary for oxidative phosphorylation.

• A
  $P$ and $Q$ are true,and $P$ is the correct explanation of $Q$.
• B
  $P$ and $Q$ are true,but $P$ is not the correct explanation of $Q$.
• C
  $P$ is true,but $Q$ is false.
• D
  $P$ is false,but $Q$ is true.