<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 43-year-old man comes to the physician because of left flank pain and nausea for 2 hours. The pain comes in waves and radiates to his groin. Over the past year, he has had intermittent pain in the bilateral flanks and recurrent joint pain in the toes, ankles, and fingers. He has not seen a physician in over 10 years. He takes no medications. He drinks 35 beers daily. His sister has rheumatoid arthritis. Vital signs are within normal limits. Physical examination shows marked tenderness bilaterally in the costovertebral areas. A photograph of the patients left ear is shown. A CT scan of the abdomen shows multiple small kidney stones and a 7-mm left distal ureteral stone. A biopsy of the patients external ear findings is most likely to show which of the following?? A: Cholesterol, B: Ammonium magnesium phosphate, C: Monosodium urate, D: Palisading granulomas, E: Calcium oxalate,  <response>: This is a multiple choice question about a patient with left flank pain and a history of recurrent joint pain. The question stem provides key details about the patients symptoms, medical history, social history, physical exam findings, and diagnostic test results. The patient has left flank pain radiating to the groin, a history of bilateral flank pain and joint pain in the toes, ankles and fingers, kidney stones shown on CT, and ear findings. The question asks which substance is most likely to be found on biopsy of the patients ear. Based on the details provided, this appears to be a case of gout, which can cause both kidney stones and deposition of urate crystals in the ear. The ear findings are described as being consistent with tophi, which are deposits of monosodium urate crystals that can form in joints, ears, and other tissues in patients with chronic gout. Of the answer choices, monosodium urate crystals would be most consistent with this clinical presentation.C: Monosodium urate 