When you join to independent clauses with a conjunction you stablishes the equality in this clauses, however in this case you can see that the clauses have a causal relation, it could be said If you don’t hold my hand, I will drown, in this case the best conjunction to put the clauses together is “or” “Hold my hand or I will drown.”
So, you may understand what is being read or said aloud.
I could see that my fire maker was having a hard time. But I gave him his space, because I wanted the warmth of the fire.
The answer is A. Hope this helps and have a nice day! ;)