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
Earliest (first) L.A. used clinically 
Select and explain. 
A. Xylocaine/Lidocaine, B. Morphine, C. Cocaine, D. Cannabis & Procaine
C: Cocaine
Answer: C: Cocaine 
Explanation: C i.e. Cocaine