This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
Confidence limit is calculated by - 
Select and explain. 
A. Mean and standard error, B. Mean and standard detion, C. Median and standard detion, D. Median
B: Mean and standard detion
Answer: B: Mean and standard detion 
Explanation: Question repeated