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: a father said his son , ` ` i was as old as you are at present at the time of your birth . ` ` if the father age is 32 now , the son age 5 years back was 
Options: a ) 11 , b ) 17 , c ) 11 , d ) 19 , e ) 99

Ex Output:
a


Ex Input:
Problem: 123 : 36 : : 221 : ? 
Options: a ) 52 , b ) 69 , c ) 72 , d ) 25 , e ) 32

Ex Output:
d


Ex Input:
Problem: if 30 % of a number is equal to one - third of another number , what is the ratio of first number to the second number ? 
Options: a ) 2 : 5 , b ) 3 : 7 , c ) 10 : 9 , d ) 7 : 3 , e ) none of these

Ex Output:

c