A 2023 study tested whether community-policing reforms reduced crime. They compared four cities that adopted reforms with matched control cities. Property-crime rate changes (%) over 3 years: City W, -8% (vs. -7% control); X, -22% (vs. -8% control); Y, -6% (vs. -5% control); Z, -28% (vs. -9% control). Researchers argued the reforms had a real effect only in Cities X and Z. The strongest support is ______
Which choice most logically completes the text using the data above?
- A
City Z's largest decline of -28%.
- B
the average decline across reform cities.
- Ccheck_circle
the contrast: Cities X and Z fell 14 and 19 points more than their controls, while Cities W and Y nearly matched their controls.
- D
City W's decline of -8%.
Explanation
"Real effect only in X and Z" requires comparing each reform city to its control. Choice B captures the 14-point and 19-point excess declines in X and Z while noting W and Y matched controls.