Final answer:
The determinant for organ compatibility and subsequent rejection of transplants is the major histocompatibility complex (MHC) molecules. These proteins are responsible for the immune system's recognition of self versus non-self, with compatibilities in these molecules being essential for successful organ transplantation.
Therefore the correct answer is option is A) major histocompatibility complex (MHC) molecules
Step-by-step explanation:
The determinant for organ compatibility and rejection of transplants is A. major histocompatibility complex (MHC) molecules. These glycoproteins are crucial in differentiating between self and non-self cells within the body. During the process of organ transplantation, such as liver, kidneys, or heart transplants, MHC tissue typing is performed to ascertain donor-recipient compatibility.
This decreases the likelihood of organ rejection. MHC molecules are highly polymorphic, meaning there are multiple alleles for each MHC gene locus, which increases the complexity of finding matches. A successful transplant typically requires compatibility in several of these polymorphic molecules. Immunosuppressive drugs like cyclosporine A are also used to reduce the probability of rejection by dampening the immune response.