Nikki packed unit cubes into a prism, as shown. Which statement about the volume of the box is true? (A): The volume of the box is more than 56 cubic units.
(B):The volume of the box is 56 cubic units.
(C):The volume of the box is less than 56 cubic units.
(D):There is not enough information to determine the volume of the box.

(Please help, i´m having difficulties. I saw a question like this but I didn't understand the answer. Thank you so much!)