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
All are true about lignocaine except – 
Select and explain. 
A. Most commonly used anesthetic agent, B. Effective for 45–60 minute, C. Safe for person prone to malignant hyperthermia, D. None
C: Safe for person prone to malignant hyperthermia
Answer: C: Safe for person prone to malignant hyperthermia 
Explanation: Lignocaine can precipitate malignant hyperthermia, therfore it should not be used in patients with history of malignant hyperthermia.
Lignocaine is the most commonly used anesthetic. Its duration of action is 45-60 min without adrenaline and 2-3 hours with adrenaline.