This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
Guthrie test can be used for the diagnosis of ? 
Select and explain. 
A. Tyrosinemia, B. Galactosemia, C. Alkaptonuria, D. Phenylketonuria
D: Phenylketonuria
Answer: D: Phenylketonuria 
Explanation: Ans. is 'd' i.e., Phenylketonuria