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
The Hb level is healthy women has mean 13.5 g/dl and standard detion 1.5 g/dl, what is the Z score for a woman iwht Hb level 15.0 g/dl- 
Select and explain. 
A. 9, B. 10, C. 2, D. 1
D: 1
Answer: D: 1 
Explanation: Ref:Parks 23rd edition pg 849 Z score = (individual value - mean) / SD =(15-13.5)/1.5= 1