We have some unknown number x and we're adding 3 to it getting x+3
To isolate x, we need to undo the operation happening to it. So we need to undo the addition of 3. We'll subtract 3 from all sides
-1 < x+3 < 5
-1-3 < x+3-3 < 5-3 ... subtract 3 from all sides
-4 < x+0 < 2
-4 < x < 2 ... answer is choice B
