A rectangular block, with dimensions 4\:cm,5\:cm and 6\:cm, is made up of cubes each with side length 1\:cm. If 1\:cm^3 cubes are removed from this larger rectangular block, what is the minimum number of these cubes that must be removed so that the resulting solid is itself a cube?
Answer Choices
A. 40
B. 93
C. 46
D. 64
E. 56