A Patient Goes to the Emergency Department Because His Arm

A patient goes to the emergency department because his arm started to swell up after being stung by a wasp. The exocytosis of histamine from the granules of the cells that possessed IgE receptors was due to the increased intracellular concentration of calcium. The process of calcium release was initiated by a trigger mechanism that depended on the

A) formation of IgE receptors by plasma cells
B) activation of adenylate cyclase
C) secretion of leukotrienes
D) release of preformed mediators
E) decrease in cyclic AMP levels