Length x width x height. Plug in the numbers, the bottom one, the length is 5, width is 3, height is 9. 5 x 3 = 15. 15 x 9 = 135. Now considering you still have the top one to do, we can eliminate A, B, and C as answer choices. But if you want proof to solve it, the top figure is length 8 x width 3 x height 3. 8 x 3 = 24. 24 x 3 = 72. 135 + 72 = 207. Recap:
Bottom Figure:
5 x 3 x 9
5 x 3 = 15, 15 x 9 = 135
Top Figure:
8 x 3 x 3
8 x 3 = 24, 24 x 3 = 72
135 + 72 = 207. There is your answer, good luck!