Analyze the steps involved in the full implantation of the blastocyst into the uterine wall.

• A. The blastocyst forms the placenta, preventing any interaction with the uterine wall.
• B. The blastocyst adheres to the endometrium, trophoblast cells invade and erode tissue, and syncytiotrophoblasts facilitate nutrient exchange.
• C. The blastocyst signals the endometrium to shed, marking full implantation.
• D. The blastocyst divides into the embryoblast and cytotrophoblast, completing implantation.

Answer: (B)