$A$: $DNA$ replication occurs only once in meiosis.
$R$: Exchange of $DNA$ in chromosomes is seen in mitosis.

• A
  $A$ is correct and $R$ is incorrect.
• B
  $A$ and $R$ both are incorrect.
• C
  $A$ and $R$ both are correct.
• D
  $A$ is incorrect and $R$ is correct.