Final answer:
A researcher testing social structure theory would most likely ask about the impact of family structure on criminal behavior, as it aligns with how sociologists investigate the influence of social factors on individual outcomes.
Step-by-step explanation:
The question most likely to be asked by a researcher testing a social structure theory is (b) What impact does family structure have on criminal behavior? This question aligns with the sociological focus on how the social environment, such as family dynamics, influences individuals' actions and outcomes, including criminal behavior. Sociologists look into how various social factors, including moral development, laws, family patterns, and other cultural rules that govern social life, play a role in behaviors and societal patterns.