Answer:
that if he wanted to live he would have to think ahead and try to stay on step ahead of her.(his mother)
Explanation:
I would say the second one- it sounds like a run on, but if you read them out loud, it's the one that sounds right. If you were to say the sentence, there's no sense in stopping and pausing your sentence after "bored". Honestly, they probably shouldn't have put the word "so" in either sentence because it doesn't flow well, but they probably did it that way to throw you off. The first one has an unnecessary pause, where the second one doesn't.
Good luck!!