问道增强题，陈向东书P390题10

题目是这样的：

In December 1992 Tideville shopping mall repaired and improved the lighting in the mall"s parking lots, and in 1993 car therfs and attempted car thefts from those lots decreased by 76% from the precious year. since potential car thieves are generally deterred by good lighting, the decrease can be attributed to those improvements.

D. in the town of Tideville, where the mall is located, the number of car therfs was about the same in 1993 as in 1992.

E. In 1993 the number of security officers patrolling the mall's parking lots at night was double.

答案是D，但是我根据题目得出的结论是因为照明系统的增加导致了小偷的下降，这进一步的结论是因为小偷不敢在有光的条件下作案，于是我选的是E。晚上的巡逻多是因为晚上光线暗，但是答案选的D，说盗贼数量没有变？这对结论没什么增强啊？

请各位NN解答下。谢谢了。