关于独立主格的问题，请斑竹入内一观

vinbobo

The Acoma and Hopi are probably the two oldest surviving Pueblo communities, both dating back at least a thousand years.
A. both dating
B. both of which have dated
C. and each has dated
D. and each one dating
E. each one of which date

这题选A可以排除出来，但是both不是指代主语么？根据我的理解，独立主格不可以与主句主语相同，否则直接用伴随状语就好了
因此很纠结
这种结构更加类似同位语吧？