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: the surface area of a sphere is 4 π r 2 , where r is the radius of the sphere . if the area of the base of a hemisphere is 3 , what is the surface area t of that hemisphere ? 
Options: a ) 6 / π , b ) 9 / π , c ) 6 , d ) 9 , e ) 12

Ex Output:
d


Ex Input:
Problem: a circular garden is surrounded by a fence of negligible width along the boundary . if the length of the fence is 1 / 3 of th area of the garden . what is the radius of the circular garden ? 
Options: a ) 6 , b ) 2 , c ) 4 , d ) 8 , e ) 16

Ex Output:
a


Ex Input:
Problem: two cubes of tire sides ratio 2 : 3 . find its cube volumes ratio ? 
Options: ['a ) 2 : 27', 'b ) 3 : 27', 'c ) 1 : 27', 'd ) 8 : 27', 'e ) 5 : 27']

Ex Output:

d