弱弱地问GWD-23-Q2

Known today by a name they would not have recognized—Anasazi, Navajo for “ancient enemies”—the ancestors of the modern Zuni and Hopi built and then, for reasons still mysterious, abandoned the complex roads and structures of the domain they ruled a millennium ago in the American southwest.

A.      ancestors of the modern Zuni and Hopi built and then, for reasons still mysterious, abandoned the complex roads and structures of the domain they ruled a millennium ago in the American southwest

B.       reasons are still mysterious why the ancestors of the modern Zuni and Hopi built and then abandoned the complex roads and structures of the domain they ruled in the American southwest a millennium ago

C.      modern Zuni and Hopi had ancestors who, a millennium ago, ruled a domain in the American southwest where they built and then abandoned complex roads and structures for still mysterious reasons

D.      domain of the American southwest was ruled a millennium ago by the ancestors of the modern Zuni and Hopi, who built and then, for reasons still mysterious, abandoned complex roads and structures

E.       complex roads and structures of the domain that the ancestors of the modern Zuni and Hopi ruled a millennium ago in the American southwest were built and then, for reasons still mysterious, abandoned

答案选A，我只想问一下，A中的they是不是指ancestors?不会与roads and structures引起歧义吗？

想问一下这个Known today by修饰的是什么呀，我一看这道题，第一反应就是，主句的主语是Known所修饰的对象，然后向那只能是modern Zuni and Hopi，我犯了什么错误呢？现在我自己看看也觉得好像不是这么想的，可是又没有NN可以解释一下呢

known修饰的是ancestors,仔细理解一下第一句话的意思