This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sex Hormones, Subject name: Physiology
A fertilized ovum reaches uterine cavity in? 
Select and explain. 
A. 3-4 days, B. 5-6 days, C. 7-8 days, D. 10 days
A: 3-4 days
Answer: A: 3-4 days 
Explanation: ANSWER: (A) 3-4 daysREF: William's obstetrics 22nd ed, Langman s Medical Embryology 9th edition page 45LH Surge24 hours before ovulationOvulation0 hoursFertilization24 hours after ovulation (Day 1)Reaches uterine cavity3-4 days post fertilization (Day 4-5 post ovulation)Implantation7-9 day post fertilization