This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
All are in cystinuria except 
Select and explain. 
A. Cystine, B. Ornithine, C. Alanine, D. Arginine
C: Alanine
Answer: C: Alanine 
Explanation: Cystinuria is one of the inborn errors of metabolism. It is autosomal recessive disorder. The disorder is attributed to the deficiency in transpo of amino acids. Abnormal excretion of cysteine and to a lesser extent lysine, ornithine and arginine. Hence the condition is also known as Cysteine-lysinuriaRef: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 219