Ursula has 5 cubes with side lengths of 1/2 inch and 24 cubes with side lengths of 1/4 inch. Together, the 29 cubes could be used to fill a rectangular prism with what dimensions?
A. 1 inch x 2 inches x 1/2 inch
B. 2 1/2 inches x 6 inches x 6 inches
C. 4 inches x 1/2 inch x 1 3/8 inches
D. 5 1/2 inches x 6 1/4 inches x 4 1/4 inches
*also, if you know the answer, I would like if you could explain how you got it,but you aren't obligated to*