Many people think that the only way to remedy the problem of crime is by increasing the number of police officers, but recent statistics show that many major cities had similar ratios of police officers to citizens, yet diverged widely in their crime rates.
Conclusion (Implied Rebuttal)
Increasing the number of cops isn't the only way to fix crime.
Evidence
Many major cities have similar ratios of police officers to citizens, yet their crime rates diverged widely.
Evaluate
The author isn't claiming police don't matter at all, or that we don't need more police. The author is using the statistics to undercut the strong claim that police count is the only way to fix crime.
Same police levels yielding different crime rates means something else must be influencing crime, alongside police count.
This argument is an implicit variation of the common Faulty Implications style of rebuttal. If they were right (that the only way to fix crime was more cops), then you'd expect cities with similar police presence to have similar crime rates. But statistics show that there are cities with similar police but very different crime rates. So, they're not right.
Goal
Pick any answer that says something accurate. The author uses statistics to undermine a strong causal claim and to suggest that Alternative influences on crime must exist.