Suppose you are laying out a floor stack area that will be a two-pallet position deep. The aisle will be 3 pallets wide. Assuming that demands are constant, which SKUs will give the best space utilization in this area in-terms of number of columns? (Answer should follow the format: SKUs with _____________ number of columns should give best space utilization when aisle width is 3 pallets and lane depth is two. Show all calculations to earn credit)