What constitutes the immune system and what role does it play in the human body?

Identify the statement that is $\text{NOT}$ correct.

Consider the following four statements $(i-iv)$ regarding kidney transplantation and select the two correct ones.
$(i)$ Even if a kidney transplant is successful,the recipient needs to take immunosuppressants for a long time.
$(ii)$ Cell-mediated immune response is responsible for the rejection of the graft.
$(iii)$ $B$-lymphocytes are responsible for the rejection of the graft.
$(iv)$ The acceptance or rejection of a transplanted kidney depends on specific interferons.

Write a note on lymphoid organs.

Antibodies are synthesized by . . . . . . .

Given below are two statements:
Statement $I$: Bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced.
Statement $II$: Both bone marrow and thymus provide micro-environments for the development and maturation of $T$-lymphocytes.
In the light of the above statements,choose the most appropriate answer from the options given below: