D. To help oxygen get into blood vessels
Answer: Implantation
Explanation:
The uterus is the main site for the implantation of the embryo. It is the place where the embryo spends 9 months in the mother.
When the male and female gamete combine they form a zygote. It gets implanted in the uterus and then there is cell division and the development of embryo takes place there only.
Any abnormalities in this region will interfere in the process of implantation.
Blood flow goes from the heart, to the lungs, and back to the heart again.
Immunotherapy is a process where diseases are treated through the activation of the immune system. It often treats cancer.
Contemporary landscapes result from many causes, including variability in abiotic conditions, such as climate, topography, and soils; biotic interactions, such as competition, mutualism, herbivory, and predation, that can generate spatial pattern even when environmental conditions are homogenous; natural disturbances. I hope this helps :)
