A newborn screening reveals elevated phenylalanine levels. Subsequent testing confirms a deficiency in phenylalanine hydroxylase. Which of the following is the most appropriate long-term dietary intervention for this infant?

✓ Correct Answer: Option B

Phenylketonuria (PKU) results from phenylalanine hydroxylase deficiency, preventing phenylalanine conversion to tyrosine. A phenylalanine-restricted diet supplemented with tyrosine is crucial to prevent intellectual disability and other neurological issues.