Think: since every glass will receive more than 2 cubes, then consider 3 cubes. Does 3 divide into any of the four given possible answers without a remainder? Does 3 divide into 13 without a remainder? Follow this process until you find the possible answer into which 3 divides without a remainder.
Eliminate 4, because none of the four given possible answers divides by 4 without leaving a remainder. What about 5? Can you divide any of the given possible answers by 5 without there being a remainder?