Q. A 35-year-old male with a history of hypertension presents to the emergency department with frequent episodes of dizziness and sweating. He reports a history of losing consciousness several times in the past month. The patient's blood glucose level is found to be 35 mg/dl and he has elevated C-peptide levels. On further examination, mild epigastric pain is noted. The patient undergoes imaging studies, and the results are pending. The patient has a family history of hypercalcemia and jejunal ulcer disease. Which of the following is the most likely diagnosis?