This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Amino acid Metabolism, 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: The bacterial inhibition assay of Guthrie is used for Phenylketonuria. Tyrosinemia- | serum AFP & succinyl acetone in serum & urine Galactosemia- urine: positive Benedict test Alkaptonuria- Gas chromatography & mass spectrometry (GCMS)