79. Phenylketonuria (PKU) and Maple Syrup Urine Disease (MSUD) are both inherited metabolic disorders affecting amino acid metabolism. Which of the following best describes between these two disorders? (A) PKU is caused by a defect in the oxidative decarboxylation of branched-chain amino acids, whereas MSUD elevated blood levels of acetoacetate and -hydroxybutyrate. (B) PKU affects the metabolism of branched-chain amino acids, while MSUD involves the transamination of an amino acid. (C) PKU is due to a deficiency in phenylalanine hydroxylase, while MSUD is caused by a defect in the oxidative decarboxylation of branched-chain amino acids. (D) Both PKU and MSUD result from impaired absorption of amino acids in the intestine. (E) PKU and MSUD are both caused by defects in the same enzyme pathway but affect different amino acids.