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: Surgery
Commonest cause of peptic ulcer disease: September 2006, March 2013(a) 
Select and explain. 
A. NSAID ingestion, B. Smoking, C. H. pylori, D. Genetic factors
C: H. pylori
Answer: C: H. pylori 
Explanation: Ans. C. H.pylori It is now widely accepted that infection with H. pylori is the most impoant factor in the development of peptic ulceration followed by NSAID ingestion. Helicobacter pylori is a Gram-negative, microaerophilic bacterium that can inhabit various areas of the stomach and duodenum. It causes a chronic low-level inflammation of the stomach lining and is strongly linked to the development of duodenal and gastric ulcers and stomach cancer. Over 80% of individuals infected with the bacterium are asymptomatic. The most reliable method for detecting H. pylori infection is a biopsy check during endoscopy with a rapid urease test, histological examination, and microbial culture. The standard first-line therapy is a one week "triple therapy"