In this task, you need to provide the correct option for a given problem on probability from the provided options.

Ex Input:
Problem: how many cubes of 5 cm edge can be cut out of a cube of 15 cm edge 
Options: a ) 36 , b ) 232 , c ) 27 , d ) 48 , e ) none of these

Ex Output:
c


Ex Input:
Problem: 4 dices are thrown at the same time . what is the probability of getting only 2 dices showing the same face ? 
Options: a ) 4 / 9 , b ) 5 / 9 , c ) 11 / 18 , d ) 7 / 9 , e ) none of the above

Ex Output:
b


Ex Input:
Problem: in how many ways can 21 books on english and 19 books on hindi be placed in a row on a shelf so that two books on hindi may not be together ? 
Options: a ) 1540 , b ) 2314 , c ) 5420 , d ) 1240 , e ) 4512

Ex Output:

a