Okay, so we basically need to find the surface area in feet.
1) 10 inches = 10/12 feet = 5/6 of a foot
2) To find the area of a side surface, we have to square the side: (5/6)^2 = 25/36
3) All right! We have six of those squares, so 6(25/36) = 150/36 = 4.166...
The closest to this is 4.17 square feet, so C is the answer.
Hope this helps!
