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: Pathology
Which of the following is a chemotactic factor: 
Select and explain. 
A. Prostaglandins, B. Prostacyclins, C. Thromboxanes, D. Leukotrienes
D: Leukotrienes
Answer: D: Leukotrienes 
Explanation: Leukotrienes