Assertion: Accurnulation of phenyl pyruvic acid in brain results in mental retardation in case of phenylketonuric.
Reason: The affcted individual lacks enzyme for the conversion of phenylalanine into tyrosine.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not correct explanation of A
(c) A is true but R is false
(d) A and R are false