This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
A patient reports a change in colour of urine on air exposure. All are true about the condition shown below except: 
Select and explain. 
A. Blackening of urine is accelerated on exposure to sunlight, B. Alkapton bodies are deposited in intervertebral disc, C. Urine Benedict's test is negative, D. Nitisinone is an inhibitor of the enzyme 4- hydroxy phenyl pyruvate dioxygenase
C: Urine Benedict's test is negative
Answer: C: Urine Benedict's test is negative 
Explanation: Ans. C. Urine Benedict's test is negativea. Alkaptonuria leads to blackening of urine which is accelerated by exposure to sunlight and oxygen.b. The alkapton bodies are polymers of Homogentisic acid and are deposited in vertebral discs, cartilage of nose, pinna.c. Benedict's test is positive with muddy yellow precipitated. Nitisinone, is an inhibitor of the enzyme 4 hydroxyphenylpyruvate dioxygenase that produces Homogentisic acid.