Some People Are Allergic to Dust Mites, Which Are Tiny

Some people are allergic to dust mites, which are tiny insects that commonly live in house dust. Which of the following is the most immediate outcome if someone who is allergic to dust mites inhales dust years after they are first exposed to dust mites?

A) IgE antibodies are produced and bind to receptors on mast cells
B) IgE antibodies bound to mast cells bind the dust mite allergen
C) IgE antibodies bound to mast cells bind to each other
D) IgE antibodies bound to mast cells trigger the production of histamine