<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 56-year-old man comes to the clinic complaining of intermittent abdominal pain for the past 2 months. He reports that the pain improves with oral intake and is concentrated at the epigastric area. The pain is described as gnawing in quality and improves when he takes his wifes ranitidine. He denies weight changes, fever, chest pain, or recent travel but endorses brain fog and decreased libido. An upper endoscopy reveals ulcerations at the duodenum and jejunum. Physical examination demonstrates bilateral hemianopsia, gynecomastia, and diffuse pain upon palpation at the epigastric area. Laboratory findings are demonstrated below:Serum:Na: 137 mEqdLCl-: 96 mEqLK: 3.9 mEqdLHCO3-: 25 mEqLGlucose: 110 mgdLCreatinine: .7 mgdLCa2: 13.5 mgdLWhat is the best explanation for this patients findings?? A: Gastrin secreting tumor of the pancreas, B: Infection with Helicobacter pylori, C: Mutation of the APC gene, D: Mutation of the MEN1 gene, E: Mutation of the RET gene,  <response>: Based on the information provided in the question stem, this patient is a 56-year-old man with intermittent abdominal pain that improves with food intake and ranitidine. He has ulcers in the duodenum and jejunum seen on endoscopy. On exam, he has bilateral hemianopsia, gynecomastia, and epigastric tenderness. Lab findings show normal electrolytes, glucose, creatinine, and elevated calcium. The ulcers, epigastric pain improving with foodantacids, and elevated calcium make me think of hypercalcemia of malignancy, likely from a secreting tumor. The bilateral hemianopsia could be explained by a pituitary tumor pressing on the optic chiasm. Gynecomastia can also occur with pituitary tumors. The elevated calcium, pituitary findings, and ulcers point me towards a diagnosis of multiple endocrine neoplasia type 1 MEN1.D: Mutation of the MEN1 gene 