Answer:
A. 7 days
Step-by-step explanation:
implantation is said to be the initial phase of pregnancy by which the embryo adhere to the walls of endometrial surface of the uterus. Through this adhesion, nutrients and oxygen are being supplied to the embryo.
The window of implantation ( i.e the period between the receptive uterus and a competent embryo) which prepares the uterus(endometrium) for its structure and what the secretions is composed of , therefore causing changes, all these happens in the bid to be able to receive the embryo. Implantation of a fertilized egg ranges from 5 to 7 days but typically last 7 days.