Final answer:
Criminologists believe that multiple variables, including sociology, psychology, and biology, influence criminal behavior.
Step-by-step explanation:
The variable that criminologists believe influences criminal behavior is:
d. All of these choices are correct.
Criminologists believe that sociology, psychology, and biology all play a role in influencing criminal behavior. Sociology helps us understand how societal factors, such as family, peers, and community, can influence an individual's criminal behavior. Psychology focuses on how individual personality traits and mental processes contribute to criminal behavior. Biology studies the biological factors, such as genetics and brain chemistry, that may contribute to criminal behavior. By studying all of these variables, criminologists gain a comprehensive understanding of the complex nature of criminal behavior.