$P -$ Statement: Simple diffusion is a process of passive transport.
$Q -$ Reason: Passive transport does not require energy.

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