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
Watson and Crick are associated with ? 
Select and explain. 
A. Discovery of helical structure of DNA, B. Association of Helicobacter pylori with chronic gastritis, C. Discovery of HIV virus, D. None of the above
A: Discovery of helical structure of DNA
Answer: A: Discovery of helical structure of DNA 
Explanation: Ans. is 'a' i.e., Discovery of helical structure of DNA