Receive, retain and nourish a fertilized ovum is the main function of:

Explanation

The blastocyst implants in the thickened endometrium of the uterus, which then supports the pregnancy through the placenta, so receiving, retaining and nourishing are all uterine functions. The oviduct is where fertilisation itself occurs, which is why it is the closest distractor, but the embryo only passes through it. The ovary releases the egg and the cervix is the muscular opening into the vagina.