Respuesta :
The correct answer is option A, thymus gland
Reason -
The thymus gland is responsible for producing T-cell for the immune system. It is usually active till puberty and then it is replaced as it shrinks down. Though this gland has a short life but it plays a major role in developing the immunity system. For instance if someone has born without a thymus gland , then the person’s body will never be able to produce T –cell or thymosin which is very essential for the immunity system development.
