So to find the surface area of a rectangular prism, you need to find the area of the adjacent sides then it it multiplied by 2. Then, add the three values, and that is how you get the surface area. In this case, the surface area given is 112 square inches. The length is 2 inches and width is 8 inches. Let us see.
To find the surface area, it should be L X W X 2, W X H X 2 and L X W X 2, and add all the product.
So upon computing, the correct answer would be 4 inches. The correct answer is the first option. When you try to substitute it, and add all the product, you will get 112. Hope this answer helps.