Assertion (a): alanine is one of the basic units of protein.
reason (r): alanine is an essential amino acid.
(A) Both the Assertion and Reason are correct and Reason is the correct explanation for Assertion.
(B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
(C) Assertion is correct but Reason is incorrect.
(D) Assertion is incorrect but Reason is correct.