Answer: D. the mucus that helps the sperm travel to the uterus is too thick.
Artificial insemination is the technique in which the sperms are introduced into the female's cervix or uterine cavity. This results in pregnancy through in vivo fertilization. Women cervix is blocked by thick mucus which block the entry of sperms. Therefore, artificial insemination would be better in such situation than other forms of treatment.
<span>The ventricles are the part of the heart that are responsible for the pumping action to move blood throughout the body. Therefore, the muscles in the ventricles are much larger and thicker to do their job properly. The atrium only has to pump blood through an open valve (the tricuspid valve) into the right ventricle. There is much less resistance to this flow of blood so much less muscle is needed. </span>
Answer: Ecosystem
Explanation: An ecosystem consists of all the biotic and abiotic factors in an area and their interactions. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted.