This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
A 55-year-old female patient presents with duodenal ulcer. The most sensitive test to detect Helicobacter pylori is 
Select and explain. 
A. Urea breath test, B. culture, C. Histology, D. Serology
A: Urea breath test
Answer: A: Urea breath test 
Explanation: Urea breath test is the most sensitive test for diagnosis of Helicobacter pylori infection. Urea breath test: The patient drinks a solution of urea labeled with a radioactive Carbon-14 and then blows into a tube. If H. pylori urease is present, the urea is hydrolyzed, and labeled carbon dioxide is detected in breath samples. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition