help!! 请教一个GWD第一套的问题

Although people in France consume fatty foods at a rate comparable to the United States, their death rates from heart disease are far lower in France.

B. people in France and the United States consume fatty foods at about the same rate, the
D. the rate of fatty foods consumed in France and the United States is about the same, the
E. the rate of people consuming fatty foods is about the same in France and the United States, the

为什么答案是B而不是D或则E呢？
是不是因为 "... a rate..." 不能和 “... rates..."比较阿， 所以是复数的”people"和“rates"比阿？？

谢谢

thanks a lot