Total surface area of a cuboid = 2(lb + bh + lh). Here lb=310, bh=20, and lh=248. So TSA = 2 × (310 + 20 + 248) = 1156 square cm. A cuboid has three pairs of equal rectangular faces: lb, bh, and lh. We add these three face areas and multiply by 2 to include the opposite faces. The answer is in square units, so the correct choice is 1156 cm².