A 40-year-old man is admitted to the hospital for severe constant abdominal pain with nausea and vomiting for 1 day with the pain radiating to the back. Past medical history is insignificant. He drinks one or two 6-packs of beer each weekend. He denies having diarrhea or fever. The serum amylase and lipase levels are markedly elevated. What is the anatomical location of the structure involved?
Completely Intraperitoneal Paially intraperitoneal Sub peritoneal Retroperitoneal