Which Event Represents the Process of Releasing Chemical Mediators

Which event represents the process of releasing chemical mediators?

A) Prostaglandins causing vasodilation and increased vascular permeability
B) Degranulation
C) Binding of IgE by the Fc region to mast cells and basophils
D) Binding of allergen to adjacent IgE binding sites on mast cells and basophils
E) Histamine acting on smooth muscle