At the end of a balanced anaesthesia technique with

At the end of a balanced anaesthesia technique with non-depolarizing muscle relaxant, a patient recovered spontaneously from the effect of muscle relaxant without any reversal. Which is the most probable relaxant the patient had received?

1.Pancuronium.
2.Gallamine.
3.Atracurium.
4.Vecuronium.

Ans. 3