24. For the last five years the Dutch economy has grown faster than Britain, France, or Germany, with the unemployment rate having remained well below that(而不是those?) of the other three countries.

A. Britain, France, or Germany, with the unemployment rate having remained

B. have those of Britain, France, or Germany, and the unemployment rate remaining

C. have Britain, France, and Germany, and the unemployment rate has rema ined

D. the economy of Britain, France, and Germany, with the unemployment rate that has remained

E. the economies of Britain, France, and Germany, and the unemployment rate has remained

选E。看了很多关于本题的讨论，对答案没有异议。我的问题是后半句unemployment rate进行比较时，为什么不是those of the other three countries,而用单数that?

如果这样，前半句里的the economies of (the other three countries)不是也应该是单数么？

confused.....请高手指点。谢谢。