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
In the rejection phenomenon after kidney transplant, the primary target for early immunological attack is - 
Select and explain. 
A. Vascular endothelium, B. Renal papillae, C. Glomeruli, D. Proximal tubules
A: Vascular endothelium
Answer: A: Vascular endothelium 
Explanation: Ans. is 'a' i.e., Vascular endothelium