In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a larger cube has 216 cubic inch as a volume and in the cube there are 216 smaller cubes such that their volume is 1 cubic inch . what is the difference between the surface areas ’ sum of the 216 smaller cubes and the surface area of the larger cube , in square inch ? 
Options: a ) 54 , b ) 64 , c ) 81 , d ) 1080 , e ) 120

Ex Output:
d


Ex Input:
Problem: what is the radius of the incircle of the triangle whose sides measure 5 , 12 and 13 units ? 
Options: ['a ) 2 units', 'b ) 12 units', 'c ) 6.5 units', 'd ) 6 units', 'e ) 7.5 units']

Ex Output:
a


Ex Input:
Problem: a rectangular tiled patio is composed of 160 square tiles . the rectangular patio will be rearranged so that there will be 2 fewer columns of tiles and 4 more rows of tiles . after the change in layout , the patio will still have 160 tiles , and it will still be rectangular . how many rows are in the tile patio before the change in layout ? 
Options: a ) 5 , b ) 6 , c ) 10 , d ) 13 , e ) 28

Ex Output:

c