In Trying to Understand the Psychology of Addiction,Dr

In trying to understand the psychology of addiction,Dr.Jackson focuses on the neurochemical changes that occur,Dr.Fong focuses on the consequences that people experience for their behaviour,and Dr.Wenkle focuses on the cognitive processes that people use in choosing their actions.Which underlying theme does the different perspectives of these three professionals help to illustrate

A)  People's experience of the world is highly subjective. 
B)  Psychology evolves in a sociohistorical context. 
C)  Psychology is empirical. 
D)  Psychology is theoretically diverse.