Which of the following is an autoimmune disorder?

The cells which suppress the entire immune system from its attack in the same body are known as

Assertion: Artificially acquired passive immunity results when antibodies or lymphocytes produced outside the host are introduced into a host.
Reason: $A$ bone marrow transplant given to a patient with genetic immunodeficiency is an example of artificially acquired passive immunity.

When an insect bites,the affected area swells. Which chemicals are likely introduced into the body?

Memory cells ............

Which antibody is obtained by the fetus from the placenta to provide immunity?