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: Dental
If the birth weight of each of the 10 babies born in a hospital in a day is found to be 2.8kg, then the standard deviation of this sample will be: 
Select and explain. 
A. 2.8, B. 0, C. 1, D. 0.28
B: 0
Answer: B: 0 
Explanation: In the given question, the birth weight of each of the 10 babies born in a hospital in a day is Count, to ht 28 kg, thus = ZERO
So the standard deviation of this sample will be,