This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Zollinger Ellison syndrome is characterized by all of the following except - 
Select and explain. 
A. Post bulbar ulcer, B. Recurrent duodenal ulcer, C. Severe diarrhoea, D. Massive HCL in response to histamine injection
D: Massive HCL in response to histamine injection
Answer: D: Massive HCL in response to histamine injection 
Explanation: None