A 25-year old male presents with a 3-month history of epigastric pain that occurs about 2 hours after meals and awakens him around 2 a.m. daily. Antacids and food give temporary relief, but the pain comes back. The APRN's diagnostic hypothesis based on these clinical manifestations is ________. 1) A diverticulosis 2) B jaundice 3) C duodenal ulcer 4) D appendicitis