跪求T-9-Q34疑惑解答！！！！！！

GMATER800

Just like the background in art history needed by an archaeologist in order to evaluate finds of ancient art, the nautical archaeologist needs specialized knowledge of the history and theory of ship design in order to understand shipwrecks.
A Just like the background in art history needed by an archaeologist in order to evaluate finds of ancient art, the
B Just as an archaeologist who needs a background in art history to evaluate finds of ancient art, a
C Just as an archaeologist needs a background in art history to evaluate finds of ancient art, so a
D Like the archaeologist who evaluates finds of ancient art and requires a background in art history, so the
E As evaluating finds of ancient art requires an archaeologist who has a background in art history, so the
答案选C，求问，既然as是连词，那么so在这里就只能是副词了吧。。。。

lvning

Just as...., so ....是一个固定句式