Autoimmune disease occurs when the body reacts against self antigens.

• A. False
• B. True
• C. Not enough information
• D. Both

Answer: (B)

Autoimmune disease arises when the immune system targets the body's own components, self antigens. Normally, the immune system uses tolerance to prevent reactions against self, but when this tolerance fails, autoreactive B and T cells can attack tissues, producing autoantibodies or cellular damage. This self-directed reactivity is the defining feature of autoimmune conditions, so the statement is true. The other options don’t fit because the concept is well established: not enough information isn’t needed, and false or both would contradict the basic idea that the immune system can attack self.