Answer:
The correct option is A) A condition that occurs when donated immune cells attack the recipient's cells.
Explanation:
Graft-versus-host disease can be described as a condition when the immune cells present in the donor attacks the immune cells of the recipient. Depending on the type of rejection, graft-versus-host disease can be mild, moderate or serious. In some cases, the body might completely reject the graft and death of the patient might occur. Hence, graft-versus-host disease can be life threatening in some cases.
