Total surface area of a cuboid = 2(lb + bh + lh). Here lb=306, bh=54, and lh=459. So TSA = 2 × (306 + 54 + 459) = 1638 square m. 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 1638 m².