Statement $X$: The skin of amphibians acts as a respiratory organ.
Statement $Y$: Amphibians lack an exoskeleton and have moist skin.

• A
  Statement $Y$ is the correct reason for Statement $X$.
• B
  Statement $Y$ is an incorrect reason for Statement $X$.
• C
  Statement $X$ is false. Statement $Y$ is irrelevant.
• D
  Both Statement $X$ and Statement $Y$ are false.