The First Social Psychology Text Was Published

The first social psychology text was published

A) in the early 1930s,when researchers examined the effects of deprivation on aggression and altruism.
B) in World War I,when psychologists conducted studies of social conflict and cooperation.
C) in World War II,when researchers performed studies of persuasion and soldier morale.
D) in the early 1900s,shortly after social psychology experiments began to be conducted.