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
In a sample of 100 pregnant females, Mean haemoglobin level estimated was 10 gm% with a Standard deviation of 1 gm%. What is the Standard error? 
Select and explain. 
A. 1 gm%, B. 0.1 gm%, C. 10 gm%, D. 100 gm%
B: 0.1 gm%
Answer: B: 0.1 gm% 
Explanation: None