Assertion $(A) :$ Phenylketonuria is an inborn error of metabolism and inherited as the autosomal dominant trait.
Reason $(R) :$ The disease is caused by mutation in the gene that codes for the enzyme phenylalanine hydroxylase.

• A
  Both $(A)$ and $(R)$ are correct and $(R)$ is the correct explanation of $(A)$
• B
  Both $(A)$ and $(R)$ are correct but $(R)$ is not the correct explanation of $(A)$
• C
  $(A)$ is correct but $(R)$ is not correct
• D
  $(A)$ is not correct but $(R)$ is correct