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: how many odd 3 - digit integers greater than 800 are there such that all their digits are different ? 
Options: a ) 40 , b ) 56 , c ) 72 , d ) 81 , e ) 104

Ex Output:
c


Ex Input:
Problem: the contents of a certain box consist of 48 apples and 30 kiwis . how many kiwis must be added to the box so that exactly 30 % of the pieces of fruit in the box will be apples ? 
Options: a ) 90 , b ) 72 , c ) 82 , d ) 54 , e ) 65

Ex Output:
c


Ex Input:
Problem: if john makes a contribution to a charity fund at school , the average contribution size will increase by 50 % reaching $ 75 per person . if there were 4 other contributions made before john ' s , what is the size of his donation ? 
Options: a ) $ 100 , b ) $ 175 , c ) $ 200 , d ) $ 250 , e ) $ 450

Ex Output:

b