How did Freud's theories about human behaviour differ from prevailing viewpoints in the early 1900s

A)  He proposed the existence of free will. 
B)  He saw people as not fully aware of the forces that control their behaviour. 
C)  He emphasized environmental forces on behaviour. 
D)  He saw abnormal behaviour as resulting from biological causes.

Freud's theories differed from prevailing viewpoints in the early 1900s because he emphasized the role of the unconscious and the fact that people are not fully aware of the forces that control their behavior. This was in contrast to the prevailing notion of the time that people were rational, conscious beings who had full control over their actions. Freud's emphasis on the unconscious and the influence of childhood experiences on adult behavior was a major departure from the prevailing viewpoints of the time.