The Philadelphia Foot Patrol Experiment, a randomized control trial conducted by Temple University, has shown that foot patrols reduce crime. With the resources to patrol 60 locations, researchers identified the highest violent crime corners in the city, using data from 2006 to 2008. Police commanders designed 120 foot patrol areas around these corners, and stratified randomization was used to assign pairs of foot patrols with similar crime rates as either a comparison or a target area. Officers generally patrolled in pairs with two pairs assigned to each foot patrol. After three months, relative to the comparison areas, violent crime decreased 23%. Adapted from Wikipedia: Patrol
Which of the following statements is the main point of this text?
(a) The crime rate is reduced by regular foot patrols.
(b) Violent crime decreased in the years from 2006 to 2008.
(c) The police conducted an experiment on foot patrols.
(d) The crime rate is lower in Philadelphia than in other places.
(e) Randomization in police experiments is important.