Answer:
306 cubic inches, or D.
Explanation:
The formula to find the volume of a rectangular prism is base times width times height, or BWH. Utilizing this formula, the rectangular prism on the left has an area of 126 cubic inches, and the rectangular prism on the right has an area of 180 cubic inches. Then, all that is left to do is add the two volumes to get the combined volume of 306 cubic inches.