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: Surgery
How much lignocaine is present in 2.0ml of 2% lignocaine solution? 
Select and explain. 
A. 40 mg, B. 20 mg, C. 30 mg, D. 2 mg
A: 40 mg
Answer: A: 40 mg 
Explanation: None