Total surface area of a cuboid = 2(lb + bh + lh). Here lb=406, bh=56, and lh=464. So TSA = 2 × (406 + 56 + 464) = 1852 square mm. 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 1852 mm².