Final answer:
Social structure theories assume that economic and social conditions play a significant role in influencing criminal behavior, rather than individual biology or personal choices alone.
Step-by-step explanation:
The assumption made by social structure theories is that economic and social conditions influence criminal behavior. These theories, such as social disorganization theory and conflict theory, suggest that crime emerges as a result of societal factors rather than individual characteristics alone. For instance, social disorganization theory indicates that conditions within a neighborhood such as poverty and limited social cohesion can result in higher rates of crime. Similarly, conflict theory, influenced by Karl Marx, posits that crime is a result of social and economic inequalities within a society. Therefore, the correct answer to the question is: d) Economic and social conditions influence criminal behavior.