This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood Physiology, Subject name: Physiology
Where does the transmigration of WBCs occur in response to infectious agents? 
Select and explain. 
A. Aerioles, B. Lymphatic ducts, C. Venules, D. Inflamed aeries
C: Venules
Answer: C: Venules 
Explanation: Transmigration of WBCs occurs through pas of the vasculature that have very thin walls and minimal vascular smooth muscle layers. This includes capillaries and venules.