This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
The interaction of antigens with antibodies on the surface of a mast cell leads to degranulation and anaphylaxis. The mast cell granules produce anaphylaxis because they contain: 
Select and explain. 
A. Lysosomes, B. Proteolytic enzymes, C. Lymphotoxins, D. Vasoactive mediators
D: Vasoactive mediators
Answer: D: Vasoactive mediators 
Explanation: None