as能否引导定语从句？

在做prep语法的时候碰到的一个题目
83. (29013-!-item-!-188;#058&003802)
Stock levels for domestic crude oil are far lower than in past years, leaving domestic oil prices vulnerable to any hints of oil supplies being disrupted in the Middle East or to any unexpected consumer demand growth possibly prompted by colder-than-normal temperatures.
(A) leaving domestic oil prices vulnerable to any hints of oil supplies being disrupted in the Middle East or to any unexpected consumer demand growth possibly
(B) leaving domestic oil prices vulnerable to any hints of oil supply disruptions in the Middle East or any unexpected growth in consumer demand that might be
(C) leaving domestic oil prices vulnerable to any hints of oil supplies that are disrupted in the Middle East or to any unexpected growth in consumer demand as was possibly
(D) resulting in the fact that domestic oil prices are vulnerable to any hints of oil supplies being disrupted in the Middle East or to any unexpected consumer demand growth possibly
(E) resulting in the fact of domestic oil prices that are vulnerable to any hints of oil supply disruptions in the Middle East or to any unexpected growth in consumer demand that might be
正确答案是B，我选的是C
但语法笔记中对于C的解释只是简单的说(C) as不能作为关系代词引导定语从句。。。然后我查了一些题目有看到过AS引导定语从句啊。。。

希望大牛能为我解惑~~~ 谢啦！