This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inflammation & Repair, Subject name: Pathology
[{'content': 'Bronchospasm is initiated by? \nSelect and explain. \nA. C5a, B. C3a, C. Leukotrienes, D. Acetylcholines', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) Leukotrienes(Ref: Robbins 9th/pg 89)LTE4 cause intense vasoconstriction, bronchospasm (importantin asthma), and increased permeability of venules.C3a, C5a, and, to a lesser extent, C4a stimulate histamine release from mast cells and thereby increase vascular permeability and cause vasodilation. They are called anaphylatoxins', 'role': 'assistant'}]