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: Medicine
Difference between upper and lower limb blood pressure is usually - 
Select and explain. 
A. 5mm, B. 10 mm, C. 30 mm, D. 35mm
A: 5mm
Answer: A: 5mm 
Explanation: None