a. RNA molecules is the correct answer.
Hope this helps~
<span>Infections
</span><span>viruses
</span>Bacteria
Mold
and so on.
The answer is; cell surface receptors that are recognized as antigens by the recipient's immune system.
Therefore the organ is attacked as a foreign substance . This is why organ transplants are given by the closest family member to reduce the antigen variability that causes transplant rejection. Tissue typing is done to ensure that the organ or tissue is as similar as possible to the tissues of the recipient.
I think its a because risk actually means exposure to danger our sacrifice your self plz mark as brainly
