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
ECG changes can first be observed when level of lignocaine is more than 
Select and explain. 
A. 5 — 6 ug/ml, B. 10 — 12 ug/ml, C. 2 — 4 ug/ml, D. 1.2 ug/ml
A: 5 — 6 ug/ml
Answer: A: 5 — 6 ug/ml 
Explanation: None