Which statement about the specific immune response is false?
a. each t or b cell has antigen receptors for only one specific antigen.
b. t and b cells recognize antigens by using antibodies bound to their surface membranes.
c. unique antigen receptors are created by genetic recombination.
d. antigens must be presented by an mhc molecule for t and b cells to recognize them.
e. all cells express mhc-i molecules, but only antigen-presenting cells express mhc-ii molecules.