It's a. Because 30 is the highest number that works out of those. (Also 3 and 2 are prime so it can't get smaller than that:) If you need an explanation of how this works, just ask. Hope it helps:) <span />
From my understanding you have 450 packs to make and you need to put 5 tissue boxes in each one so we would just simply multiply 450 packages by 5 tissue boxes each package and get 2250