Which Statement Best Summarizes the Findings of a Recent Analysis

Which statement best summarizes the findings of a recent analysis of a crackdown on street-level narcotics dealers by undercover officers?

A) Crackdowns significantly lowered crime long-term.
B) Crackdowns had a significant deterrent effect immediately (and for six months afterward) , but more long-term research is needed.
C) Crackdowns only increase intolerance for rules in the offender population, resulting in even more resistance.
D) Crackdowns don't work initially, but after a while, results can be seen.