Where does the fertilized cell (egg) attach itself for the remainder of the
pregnancy?

A fertilized egg, or zygote, takes about five days to reach the uterus from the uterine tube. As it moves, the zygote divides and develops into a blastocyst, with an inner mass of cells and a protective outer ring. The blastocyst attaches to the wall of the uterus and gradually implants itself into the uterine lining.

The fertilized egg attaches itself, to the wall of the uterus and implants itself into the uterine lining.

The answer is b. increased blood flow reduces nerve sensitivity