[E]OG-104，请指点！

excellent

104. The diet of the ordinary Greek in classical times was largely vegetarian--vegetables, fresh cheese, oatmeal, and meal cakes, and meat rarely.
A.and meat rarely
B.and meat was rare
C.with meat as rare
D.meat a rarity
E.with meat as a rarity

答案是E。请问E中的as是什么功能？as的用法实在是灵活，我有点糊涂了。

halcyon

可以理解成“作为”