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.
Explanation: the reason is that O type blood can donate to type A, B, AB and O is Compatible to other type of blood - but Kidney transplants need the same type of blood.