The antibodies are produced by the

$A$ patient rejects a transplanted kidney because of ..........

In the list given below,how many are secondary lymphoid organs?
Thymus,Spleen,Bone marrow,Tonsil,Appendix

Given below are two statements:
Statement $I:$ Autoimmune disorder is a condition where the body's defense mechanism recognizes its own cells as foreign bodies.
Statement $II:$ Rheumatoid arthritis is a condition where the body does not attack self-cells.
In the light of the above statements,choose the most appropriate answer from the options given below:

How many types of memory cells are there in the immune system?

Which cells in the body secrete lymphokines or interferons?