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'.

Input: Consider Input: Problem: marcella has 27 pairs of shoes . if she loses 9 individual shoes , what is the greatest number of matching pairs she could have left ? 
Options: a ) 22 , b ) 20 , c ) 19 , d ) 16 , e ) 15

Output: a


Input: Consider Input: Problem: if a : b = 2 : 3 , b : c = 4 : 5 and c : d = 5 : 9 then a : d is equal to : 
Options: a ) 11 : 17 , b ) 8 : 27 , c ) 5 : 9 , d ) 2 : 9 , e ) none

Output: b


Input: Consider Input: Problem: a sum of money is to be distributed among a , b , c , d in the proportion of 6 : 2 : 4 : 3 . if c gets $ 500 more than d , what is d ' s share ? 
Options: a ) $ 2000 , b ) $ 2500 , c ) $ 3000 , d ) $ 3600 , e ) $ 4200


Output: c