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
There is a population of 20000 people with mean hemoglobin being 13.5 gm% having a normal distribution. What proportion of population constitutes proportion more than 13.5 gm%? 
Select and explain. 
A. 0.25, B. 0.5, C. 1, D. 0.34
B: 0.5
Answer: B: 0.5 
Explanation: In a Normal distribution, 50% of values lie above Mean (or Median or Mode)