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: which is the smallest no which divides 2880 and gives a perfect square ? 
Options: ['a ) 4', 'b ) 9', 'c ) 3', 'd ) 5', 'e ) 7']

Ex Output:
d


Ex Input:
Problem: if the diameter of circle r is 60 % of the diameter of circle s , the area of circle r is what percent of the area of circle s ? 
Options: ['a ) 50 %', 'b ) 46 %', 'c ) 36 %', 'd ) 26 %', 'e ) 38 %']

Ex Output:
c


Ex Input:
Problem: a diagonal of a polygon is an segment between two non - adjacent vertices of the polygon . how many diagonals does a regular 40 - sided polygon have ? 
Options: a ) 875 , b ) 740 , c ) 1425 , d ) 2025 , e ) 2500

Ex Output:

b