Thanks, I get the conditional part (there are conditionals in all three options).
What I was stuck on was why the second option was wrong, not why the first was right.
The book actually gives an explanation that makes sense to me, now that I've looked at it more clearly.
It says: Aの前はBの状態が続く。
Implying that B must be a situation that continues, not a certain event that fails to happen.
I was thinking about the meaning in the sense (Unless A happens, B won't happen). Which makes sense for option b.
Perhaps a better way is to think of the てから part more specifically like Vempele said, and make it "not until after A happens, can B happen" which doesn't make any sense if there is a time specified in A.
But the でない part still bugs me...Is it from 出る?
What I was stuck on was why the second option was wrong, not why the first was right.
The book actually gives an explanation that makes sense to me, now that I've looked at it more clearly.
It says: Aの前はBの状態が続く。
Implying that B must be a situation that continues, not a certain event that fails to happen.
I was thinking about the meaning in the sense (Unless A happens, B won't happen). Which makes sense for option b.
Perhaps a better way is to think of the てから part more specifically like Vempele said, and make it "not until after A happens, can B happen" which doesn't make any sense if there is a time specified in A.
But the でない part still bugs me...Is it from 出る?