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: Unknown
The pressure used in pneumatic tourniquet in upper limb is upto: 
Select and explain. 
A. Systolic Blood Pressure + 50, B. Systolic Blood Pressure + 75, C. Systolic Blood Pressure + 100, D. None of the above
B: Systolic Blood Pressure + 75
Answer: B: Systolic Blood Pressure + 75 
Explanation: Pneumatic tourniquet is a narrow rubber bag to be wound around a limb, pressure being applied by pumping air into the inflatable cuff.
A bloodless field is obtained by applying pressure through pneumatic tourniquet for accurate surgery. Usually pressure applied 75 mmHg over systolic blood pressure for not more than 2 hours.