70 ft^2 ( choice D )
Work Shown:
L = 8 ft = lengthW = 3 ft = widthH = 1 ft = height
SA = surface area of the rectangular prism (aka block or box)
SA = 2*(LW + LH + WH)
SA = 2*(8*3 + 8*1 + 3*1)
SA = 2*(24 + 8 + 3)
SA = 2*(35)
SA = 70 square feet
This is the amount of wrapping paper you would need to cover all six sides of the box. This assumes that there are no gaps or overlaps.