This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
The most rapidly acting nondepolarizing neuromuscular blbcking agent which can be used as an alternative to Succinylcholine for tracheal intubation is: 
Select and explain. 
A. Rocuronium, B. Pancuronium, C. Doxacurium, D. Pipecuronium
A: Rocuronium
Answer: A: Rocuronium 
Explanation: (Ref: KDT 6/e p345) Rocuronium is the fastest acting non-depolarizing muscle relaxant (NDMR). It can be used for the rapid sequence endotracheal intubation in patients having contra-indications to the use of SCh. Mivacurium is the shoest acting NDMR. SCh is the shoest and fastest acting skeletal muscle relaxant. It is a depolarizing NM blocker.