‘Second line of defence' is known as

$B$-cells are lymphocytes which produce the humoral immunity. These cells are produced by

Assertion : Organ transplantation patients are given immunosuppressive drugs.

Reason : Transplanted tissue has antigens which stimulate the specific immune response of the recipient.

Identify $X$ from Figure 

Draw and describe the structure of antibody?

Select the lymphoid organs from the given choices

$I$. Lymph node $II$. Thymus gland

$III$. Red bone marrow $IV$. liver

$V$. Spleen $VI$. Osteocytes

$VII$. Peyer's patches

The correct option with correct choices is