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: if the area of a circle is 16 pi square feet , find its circumference . 
Options: a ) 8 pi feet , b ) 28 pi feet , c ) 38 pi feet , d ) 48 pi feet , e ) 58 pi feet

Ex Output:
a


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: in a certain parallelogram the degree measure of one angle exceeds that of the other by 20 what is the degree measure of the smaller angle ? 
Options: a ) 75 , b ) 80 , c ) 85 , d ) 90 , e ) 95

Ex Output:

b