Which types of cells are produced during the clonal selection of $B$-cells?

In $T$-lymphocytes,what does the letter '$T$' stand for?

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:

Antibodies fight against

Assertion: Interferons are a type of antibodies produced by body cells infected by bacteria.
Reason: Interferons stimulate inflammation at the site of injury.

What are $IgA$ and $IgM$?