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: Pathology
Helicobacter pylori is a causative agent for which of the following conditions? 
Select and explain. 
A. MALT, B. Gastric adenocarcinoma, C. Ulcers, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: None