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
Most potent chemoattracatant is: 
Select and explain. 
A. Leukotriene B4, B. Leukotriene C4, C. Leukotriene D4, D. Leukotriene E4
A: Leukotriene B4
Answer: A: Leukotriene B4 
Explanation: Ans. a. Leukotriene B4