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: what is the measure of the radius of the circle inscribed in a triangle whose sides measure 4 , 11 and 12 units ? 
Options: ['a ) 1.6 units', 'b ) 6 units', 'c ) 3 units', 'd ) 5 units', 'e ) 12 units']

Ex Output:
a


Ex Input:
Problem: if the radius of the sphere is 14 m . then its total surface area is 
Options: ['a ) 2644', 'b ) 2446', 'c ) 2464', 'd ) 6442', 'e ) 6424']

Ex Output:
c


Ex Input:
Problem: the area of a parallelogram is 243 sq m and its altitude is three times the corresponding base . what is the length of the base ? 
Options: a ) 4 , b ) 9 , c ) 10 , d ) 4 , e ) 12

Ex Output:

b