<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 25-year-old man comes to the office because of pain in his left shoulder. He says that this pain started 3 years ago and has progressively worsened. He denies joint trauma, fever, dysuria, or morning stiffness. He says that his urine turns black after it is exposed to air and has done so since childhood. He has one sexual partner and they regularly use condoms. His pulse is 72min, respiratory rate is 18min, temperature is 37.2C 99.0F, and blood pressure is 13580 mm Hg. Physical examination shows bilateral scleral darkening and point tenderness upon palpation of his right elbow, left knee, and shoulder. Leukocyte count is 6,000mm3. Which of the following enzymes is most likely deficient in this patient?? A: Branched-chain alpha-ketoacid dehydrogenase, B: Cystathionine synthase deficiency, C: Homogentisic acid oxidase, D: Phenylalanine hydroxylase, E: Propionyl-CoA carboxylase,  <response>: This is a clinical vignette describing a 25-year-old man with progressive left shoulder pain and other symptoms. The key findings are dark urine after exposure to air since childhood, scleral darkening, low leukocyte count, and point tenderness in multiple joints. This suggests a diagnosis of alkaptonuria, which is caused by deficiency of homogentisic acid oxidase. This enzyme is involved in the breakdown of tyrosine and phenylalanine. Deficiency leads to accumulation of homogentisic acid which is excreted in urine and turns black on exposure to air. The other enzymes listed are not directly related to the clinical findings described.C: Homogentisic acid oxidase 