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: Social & Preventive Medicine
The association between oral cancer and tobacco chewing was found to be as follows 
Select and explain. 
A. 0.65, B. 0.8, C. 1.3, D. 2.25
D: 2.25
Answer: D: 2.25 
Explanation: None