These antibodies stay attached to the B cell's plasma membrane and serve as receptors for binding with antigen and activating complement.

A) IgA only
B) IgG
C) IgM
D) IgE only
E) both IgE and IgA

Immunoglobulin

Any of a class of proteins present in the serum and cells of the immune system, which function as antibodies.

Plasma Membrane

The lipid bilayer membrane surrounding a cell that controls the passage of substances in and out, maintaining the cell's internal environment.