Select the incorrect statement with respect to acquired immunity.

Thymus is the site for the development and maturation of

Lymph nodes are secondary lymphoid organs. Explain the role of lymph nodes in our immune response.

Identify the enzyme associated with the production of $B$-lymphocytes and $T$-lymphocytes.

Read the following statements and choose the correct set of statements $:$
$(a)$ Cell-mediated immune response is responsible for the graft rejection.
$(b)$ Grafts from just any source $-$ an animal,another primate,or any human beings can be made since the grafts would be accepted sooner or later.
$(c)$ The organs cannot be taken from just anybody for transplant.
$(d)$ Tissue matching,blood group matching are essential before undertaking any graft/transplant.
Choose the correct answer from the options given below $:$

The injection of serum from a horse,which has been repeatedly injected with cobra venom,into a person bitten by a cobra results in: