Prism A is shown below. The height Prism B is 2 times the height of Prism A. The
length and width of both prisms are the same.

looking at the picture of prims A, the front has 5 cubes in one row and towards the back it has 3 cubes deep, so one row is 5x3 cubes or 15 cubes, prims A has two of those rows that means prims A is 30 cubes total and since each cube is 1in³, so prism A is 30 in³.

we know that prism B is twice the height of prism A but the same width, 5 cubes, and the same length, 3 cubes, so prism B is really just like prims A but with two extra rows, each row of 15 cubes.

After all that mumble jumble, we can see that since prism A has two rows of 15 cubes and prism B has 4 rows of 15 cubes, 4 rows of 15 cubes is 4x15 = 60 cubes, or 60 in³.

a. is correct