Which cells help $B$-cells in the production of antibodies?

Which group of cells acts as phagocytes?

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

Regarding kidney transplantation,four statements are given below. Select the correct statements.
$i.$ During kidney transplantation,the recipient's immune system is suppressed for a long time.
$ii.$ Cell-mediated immunity is responsible for the rejection of the transplant.
$iii.$ $B$-lymphocytes are responsible for the rejection of the transplant.
$iv.$ Specific interferons are responsible for the acceptance or rejection of the kidney transplant.
Select the correct option:

The immune system:

Which of the following secretes interferons?