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 rectangular block 10 cm by 20 cm by 30 cm is cut into an exact number of equal cubes . find the least possible number of cubes ? 
Options: a ) 6 , b ) 10 , c ) 15 , d ) 40 , e ) 22

Ex Output:
a


Ex Input:
Problem: a rectangular rug with side lengths of 2 feet and 7 feet is placed on a square floor that has an area of 64 square feet . if the surface of the rug does not extend beyond the area of the floor , what fraction of the area of the floor is not covered by the rug ? 
Options: ['a ) a . 3 / 16', 'b ) 1 / 4', 'c ) c . 1 / 2', 'd ) 25 / 32', 'e ) 7 / 8']

Ex Output:
d


Ex Input:
Problem: the radius of the base of cone is 3 cm and height is 4 cm . find the volume of the cone ? 
Options: ['a ) 12', 'b ) 75', 'c ) 97', 'd ) 15', 'e ) 91']

Ex Output:

a