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: Anaesthesia
Conc. of Lidocaine used in spinal anesthesia 
Select and explain. 
A. 5%, B. 3%, C. 2%, D. 1%
A: 5%
Answer: A: 5% 
Explanation: A i.e. 5%