Transplantation of organs is necessary when:

Organs are failing to function

The correct answer is Option (1) - Organs are failing to function.

Transplantation of organs becomes necessary when the organs in the recipient's body are failing to function properly. This can occur due to various reasons such as disease, injury, or congenital defects. When the functionality of an organ is severely compromised and cannot be restored through other medical interventions, transplantation is considered as a treatment option.

During organ transplantation, a healthy organ from a donor is surgically implanted into the recipient's body to replace the dysfunctional organ. This procedure aims to restore the normal function of the organ and improve the recipient's overall health and quality of life.

It is important to note that transplantation does not directly address issues related to antibodies, immune system weakness, or B-lymphocyte dysfunction. These factors may have implications for the success of the transplantation process, as the recipient's immune system needs to be carefully managed to prevent rejection of the transplanted organ. However, the primary reason for transplantation is the failure of the recipient's organ, and the procedure itself focuses on replacing the non-functioning organ with a healthy one.