Question

in many modern hospitals, the blood of newborn infants is routinely screened for high levels of phenylalanine hydroxylase. phenylalanine. all of these phenylpyruvic acid.

Explanation:

Newborns are screened for phenylketonuria (PKU), a disorder where phenylalanine cannot be properly metabolized. High - levels of phenylalanine are indicative of PKU. Phenylalanine hydroxylase is the enzyme that metabolizes phenylalanine and its levels are not what is screened for directly. Phenylpyruvic acid is a by - product of abnormal phenylalanine metabolism and while related, the primary screening is for high phenylalanine levels.

Answer:

B. phenylalanine