求问一道语法题 虽然不难但是感觉挺奇怪的 各位大NN帮帮忙啊

占莫

Linguist Carin Zinter, who studies the languages of ancient civilizations, is still mystified as to how the written word arose so rapidly at the same time in history across many different cultures.A.is still mystified as to how the written word arose
B.are still mystified as to how the written word arose
C.are still mystified as to how the written word arises
D.is still mystified as to how the written word arises
E.is still mystified as to how the written word is arising

占莫

求回答 为什么用arose 而不用arises ？？？

yiqing2012

这不是过去的事嘛~~~at the same time in history 完全点明了这一点啊~