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
Persons with the greatest risk of oral cancer 
Select and explain. 
A. Have a poor oro-dental hygiene, nutritional deficiencies and are chronic alcoholics, B. Are middle aged, have a poor oro-dental hygiene and regularly use tobacco, C. Are old, Chronic alcoholics and regularly use tobacco, D. Are young, have poor oro-dental hygiene and are heavy smokers
C: Are old, Chronic alcoholics and regularly use tobacco
Answer: C: Are old, Chronic alcoholics and regularly use tobacco 
Explanation: None