A 45 year old gentleman has undergone truncal vagotomy and pyloroplasty for bleeding duodenal ulcer seven years ago.Now he was intractable recurrent symptoms of peptic ulcer.All of the following suggest the diagnosis of Zollinger Ellison syndrome, except -

• A. Ulcers in proximal jejunum and lower end of esophagus
• B. Serum gastrin value of 200 pg/ml with secretin stimulation
• C. Basal acid output of 15 meq/hour
• D. Serum gastrin value of 500 pg/ml