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: Physiology
Which of the following defines hematocrit:March 2013 
Select and explain. 
A. Number of erythrocytes in blood, B. Percentage of the blood, by volume, occupied by erythrocytes, C. Ratio of erythrocytes to leucocytes, D. Ratio of erythrocytes to all blood cells
B: Percentage of the blood, by volume, occupied by erythrocytes
Answer: B: Percentage of the blood, by volume, occupied by erythrocytes 
Explanation: Ans. B i.e. Percentage of the blood, by volume, occupied by erythrocytesHematocritIt is also known as packed cell volume (PCV) or erythrocyte volume fraction (EVF)It is the volume percentage (%) of red blood cells in bloodIt is normally about 45% for men and 40% for women.