C The game is not fair and they should stop playing
So basically we can check them all by multiplying all of the dimensions.
A: 3 * 3 * 40 = 360, so yes, it could be the dimensions
B: 4 * 4 * 20 = 320, so no, it couldn't be the dimensions
C: 6 * 6 * 10 = 360, so yes, it could be the dimensions.
D: 2.5 * 12 * 12 = 360, so yes, it could be the dimensions.
E: 3.6 * 10 * 10 = 360, so yes, it could be the dimensions.
I hope this helped :)