Final answer:
Modern-day criminal street gangs often form in areas with high levels of social disorganization, where weak social ties and lack of social control contribute to crime.
Step-by-step explanation:
The statement about modern-day criminal street gangs that is true is c) Gangs often form in areas with high levels of social disorganization. Social Disorganization Theory suggests that crime is most likely to occur in communities where there are weak social ties and a lack of social control.
Factors that predict an elevated crime rate include poverty, ethnic heterogeneity, and residential mobility, which can hinder the development of a cohesive community capable of self-regulation and lower crime rates.