This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
Malignant transformation is commonly seen in: 
Select and explain. 
A. Stomal ulcer, B. Gastric ulcer, C. Chronic duodenal ulcer, D. Postbulbar ulcer
B: Gastric ulcer
Answer: B: Gastric ulcer 
Explanation: Ans. (b) Gastric ulcer* Malignant transformation is very rarely seen in gastric ulcer (<1%) - Not so common.* Giant gastric ulcer (>2cm) is associated with cancer in 6-15% cases* Of the above choices we can opt for choice B' only - but it is not so common.