An epitope is
a. The part of an interferon that binds to a foreign cell
b. A part of an antigen that binds to an antigen receptor
c. The variable region of a B cell antigen receptor
d. The part of an antigen receptor that binds to an antigen
e. A soluble form of a B cell antigen receptor
Answer: b. A part of an antigen that binds to an antigen receptor