Burger (2009) Recently Conducted a Replication of Milgram's Studies on Obedience

Burger (2009) recently conducted a replication of Milgram's studies on obedience. One of the modifications to Milgram's original method was that Burger stopped the study after participants had reached 150 volts (rather than 450) . Why did he choose the 150-volt cut-off point?

A) In Milgram's work, participants who were going to disobey usually did so by 150 volts.
B) Burger actually had the participants hooked up to the shock device with the learner, and 150 volts is quite painful.
C) 150 volts of electricity sounds very painful to participants.
D) 150 volts of electricity actually isn't painful at all.