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
Which is not a criteria for overcrowding ? 
Select and explain. 
A. No. of persons, B. Sex separation, C. Door and window, D. Floor space
C: Door and window
Answer: C: Door and window 
Explanation: Ans. is 'c' i.e., Door and window