Phenylketonuria (PKU) Is a Recessive Human Disorder in Which an Individual

Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately break down the amino acid phenylalanine. This amino acid is not naturally produced by humans. Which of the following treatments would be most effective for people with PKU?

A) Feed the individual the substrate that can be metabolized into phenylalanine.
B) Regulate the individual's diet to severely limit the uptake of phenylalanine.
C) Feed the individual the missing enzymes in a regular cycle, such as twice per week.
D) Feed the individual an excess of the missing product.