[求教]一道语法题

红叶夕歌

Native American burial sites dating back 5,000 years indicate that the residents of Maine at that time were part of a widespread culture of Algonquian-speaking people.
(A)were part of a widespread culture of Algonquian-speaking people.
(C)were people who were part of a widespread culture that was Algonquian-speaking.

wangjieava23

这个是不是选C呀， resident 只能是people 对等呀， 不能和culture 对等。