Which of the following is an autoimmune disease?

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:

$A$ condition that occurs when the immune system mistakenly attacks and destroys healthy body tissue is called

Which type of innate barrier does the $Stratum$ $corneum$ represent?

What is the full form of $MALT$?

Which cells are responsible for cell-mediated immunity?