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
Delayed prolonged increase in vascular permeability in inflammation is due to: 
Select and explain. 
A. Interleukin 1 mediated endothelial retraction, B. Increased transcytosis, C. Leakage from newly formed blood vessels, D. Release of histamine causing endothelial contraction
A: Interleukin 1 mediated endothelial retraction
Answer: A: Interleukin 1 mediated endothelial retraction 
Explanation: None