This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Misc., Subject name: Microbiology
Immune IgE receptor on mast cell in response to parasite involve mechanism of 
Select and explain. 
A. Cocaine, B. Opioid, C. Cannabis, D. All of the above
B: Opioid
Answer: B: Opioid 
Explanation: (B) Opioid # Mast cells have a number of on their cell surface. They express the high effinity surface receptor for the Fc portion of the IgE molecule (Fc&RI).> Antigenic specific binding allows for cross-linking og IgE molecules that have bound to Fc & RI on the mast cell surface.> This initiates a sequence of calcium & energy dependent events that culminate in fusion of granules to the plasma membrane, eventuating in release of the granule contents.> Degranulation & release of potent prostinoids, histamines, & inflammatory cytokines can rapidly recruit inflammatory cells.> Mast cells also express Opioid, Adenosine & beta-adrenergic receptors, &, as a result mast cell stimulation can proceed through actions independent of Fc&RI.> Non antigenic stimuli include Opiates, C5a Anaphylatoxin, Stem cell factor & Substance P.