All you have to do is basically as you said, drop the e in exposure and add -ure to the end.
Exposure
im reading the book now, so give me a few minutes and ill answer the best i can!
I'm assuming we're talking about The Hobbit and/or LOTR. If not, SORRY!!
But it would be C, they are all unwilling to help anyone but themselves.
Hope this helps luv yuh <3