This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Watson and crick are known for: 
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: Watson and Crick discovered helical structure of DNA and won a noble prize for it (Ref: TEXTBOOK OF MEDICAL PHYSIOLOGY - GEETHA)