**Core Concept**
Phenylketonuria (PKU) is a genetic disorder characterized by the inability to break down the amino acid **phenylalanine** due to a deficiency in the enzyme **phenylalanine hydroxylase**. This leads to the accumulation of phenylalanine and its metabolites in the body, causing neurological damage if left untreated.

**Why the Correct Answer is Right**
The correct answer is not provided, however, a true statement regarding a 3-week-old child with PKU would involve the importance of early diagnosis and treatment to prevent intellectual disability and other complications. **Phenylalanine** levels are typically elevated in PKU patients, and a **low-phenylalanine diet** is often prescribed to manage the condition.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option text, it's challenging to provide a detailed explanation. However, any option suggesting that PKU is not a serious condition or does not require prompt treatment would be incorrect.
**Option B:** Similarly, without the text, it's difficult to address. But if it downplays the importance of dietary restrictions in managing PKU, it would be wrong.
**Option C:** This option might be incorrect if it suggests that PKU does not have a significant impact on neurological development or if it implies that the condition can be managed without medical supervision.
**Option D:** If this option ignores the genetic basis of PKU or suggests that it is not an autosomal recessive disorder, it would be incorrect.

**Clinical Pearl / High-Yield Fact**
A crucial point to remember is that **newborn screening** programs are essential for the early detection of PKU, allowing for the initiation of treatment before significant neurological damage occurs.

**Correct Answer:**