Why Were the Nuremberg War Crime Trials a Defining Event

Why were the Nuremberg War Crime Trials a defining event for formal procedures for protection of participants?

A) Nazi's tested their authority during World War II.
B) Information was withheld from participants before, during, and after the experiments.
C) They exposed horrific medical experiments were conducted in the name of "science."
D) The trials showed people were likely to obey formal authority.