In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: find the average of first 4 multiples of 15 ? 
Options: a ) 10 , b ) 12.6 , c ) 22.5 , d ) 31.3 , e ) 37.5

Ex Output:
e


Ex Input:
Problem: when 1 / 20 % of 4,000 is subtracted from 1 / 10 of 4,000 , the difference is 
Options: a ) 50 , b ) 200 , c ) 380 , d ) 398 , e ) 400

Ex Output:
d


Ex Input:
Problem: a rope of which a calf is tied is increased from 10 m to 23 m , how much additional grassy ground shall it graze ? 
Options: a ) 1217 , b ) 1348.2 , c ) 1210 , d ) 1212 , e ) 1312

Ex Output:

b