191. (GWD-10-Q24) 请教这道题的一点疑问

turboswm

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 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 remained

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

这道题选E没有疑问，解释中有这样一段说明：而本题后半句the unemployment rate has remained well below that of the other three countries中后面没有用unemployment rates，按照规则比较结构中单复数不一致、时态不一致都是要重新补出的，但是这里用了that，说明后面用的是单数。并且GMAT不会那么荒谬地认为那三个国家公用一个unemployment rate，所以说明仅使用that即已可以表达出三个国家各自的增长率。
我想问这里为什么不用those，三个经济体的unemployment rate必然不同，为什么可以用that。