A cube is six sided. The numbers which are greater than 4 in a cube are 5 and 6. So, there are two sides on the cube which has numbers greater than 4.
Hence, the number of desired outcomes, N=2.
Since the cube is six sided, the total number of outcomes, T=6.
So, the probability of getting a number greater than 4 while rolling a cube is,

Therefore, the probability of getting a number greater than 4 is 1/3.
Option B is correct.