This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
After how many days of ovulation, embryo implantation occurs in the uterine cavity : 
Select and explain. 
A. 3-5 days, B. 7-9 days, C. 10-12 days, D. 13-15 days
B: 7-9 days
Answer: B: 7-9 days 
Explanation: Implantation can be defined as the process by which the blastocyst penetrate the epithelium and then the circulatory system of the mother It occurs 7-9 days after feilization Reference: Textbook of Obstetrics; Sheila balakrishnan; 2nd edition; Page no: 57