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
If a 95% Confidence Interval for the prevalence of cancer smokers aged > 65 years is 56% to 76%, the chance that the prevalence could be less than 56% is - 
Select and explain. 
A. Nil, B. 44%, C. 2.50%, D. 5%
C: 2.50%
Answer: C: 2.50% 
Explanation: In this question:
56 to 76 confidence interval covers 95% (2SD) of values.
That means 5% of values will fall outside the range of 56-76 → 2.5% values will be below 56 and 2.5% values will be above 76.