What is the correct sequence of events for activation of a b cell by a t-dependent antigen? (1) the b cell binds to a cytokine and then interacts with the th cell. (2) this causes the b cell to bind the antigen, and then the b cell is activated. (1) immunoglobulin receptors on the b cell recognize and bind the antigen. (2) an antigen fragment in complex with mhc class 2 is displayed on the b cell's surface. (3) the mhc-antigen complex binds a receptor on a th cell. (4) the th cell secretes cytokines that activate the b cell. (1) identical repeating subunits on the antigen bind to many of the antibodies on the surface of the b cell. (2) this activates the b cell. (1) the t cells bind to an antibody on the b cell. (2) the t cell secretes cytokines. (3) the b cell binds the antigen. (4) the b cell is activated by binding to the antigen.