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
Epidemiological studies of H. Pylori are done by using - 
Select and explain. 
A. Urea-breath test, B. Serological markers, C. Culture, D. Gastric-biopsy urease test
B: Serological markers
Answer: B: Serological markers 
Explanation: None