How Is the Immune System Able to Recognize a Limitless

How is the immune system able to recognize a limitless number of different antigens and epitopes?

A) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope.
B) Each lymphocyte is coated with many different receptors, each of which recognizes a different epitope AND the immune system produces a wide variety of lymphocytes.
C) While each lymphocyte carries receptors that recognize only one type of epitope, the immune system produces a wide variety of lymphocytes each of which carries unique receptors.
D) If a lymphocyte encounters an antigen it does not recognize, it immediately switches receptors until it finds one that is a match.
E) A genetic "memory" of the pathogens your parents encountered (and their parents and so on) is passed on to each generation, increasing the number of possible responses over time.