Max cut oft duration for prolonged seizures post ECT according to American psychiatric society:

Ans. d. 180 secondsThe first behavioral sign of seizure is often plantar, extension, which lasts 10-20 seconds and makes a tonic phase.For monitoring seizure, it should last at least 25 seconds.The onset of seizures activity is sometimes delayed as long as 20-40 seconds after the stimulus administration.Prolonged seizures lasting more than 180 seconds and status epilepticus can be terminated either with additional dose of the barbiturate agent or with IV diazepam (Valium) (5-10 mg).