A right rectangular prism is packed with cubes of side length 1/2 inch. If the prism is packed with 5 cubes along the length, 3 cubes along the width, and 6 cubes along the height, what is the volume of the prism?
A 3 3/4 cubic inches
B 7 cubic inches
C 11 1/4 cubic inches
D 24 cubic inches