Which of the Following Is a Defining Characteristic of Biologically

Which of the following is a defining characteristic of biologically oriented psychologists?  

A) They believe that self-awareness, experience, and choice permit us to invent ourselves and our ways of relating to the world as we progress through life. 
B) They study the influences of ethnicity, gender, culture, and socioeconomic status on behavior and mental processes. 
C) They investigate the ways we perceive and mentally represent the world, remember the past, plan for the future, solve problems, form judgments, make decisions, and use language. 
D) They study the role of heredity in behavior and mental processes such as psychological disorders, criminal behavior, and thinking.