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: Gynaecology & Obstetrics
In pregnancy, calculation of EDD (expected date of delivery) considers: March 2013 
Select and explain. 
A. First day of last menstruation, B. Last day of last menstruation period, C. Mid time of last menstrual period, D. Day of coitus
A: First day of last menstruation
Answer: A: First day of last menstruation 
Explanation: Ans. A i.e. First day of last menstruation