Assertion $(A)$: The structure of an enzyme consists of an apoenzyme and a coenzyme.
Reason $(R)$: $A$ coenzyme is a non-protein part that makes the enzyme active.

• A
  $A$ and $R$ are both true and $R$ is the correct explanation of $A$.
• B
  $A$ and $R$ are both true but $R$ is not the correct explanation of $A$.
• C
  $A$ and $R$ are both false.
• D
  $A$ is true but $R$ is false.