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: which number need to add to 7844213 to get a number exactly divisible by 549 ? 
Options: a ) 418 , b ) 148 , c ) 448 , d ) 248 , e ) 348

Ex Output:
c


Ex Input:
Problem: a certain social security recipient will receive an annual benefit of $ 12,000 provided he has annual earnings of $ 9,360 or less , but the benefit will be reduced by $ 1 for every $ 3 of annual earnings over $ 9,360 . what amount of total annual earnings would result in a 55 percent reduction in the recipient ' s annual social security benefit ? ( assume social security benefits are not counted as part of annual earnings . ) 
Options: a ) $ 15,360 , b ) $ 17,360 , c ) $ 25,560 , d ) $ 21,360 , e ) $ 27,360

Ex Output:
c


Ex Input:
Problem: if n is a positive integer and n ^ 2 is divisible by 18 , then what is the largest positive integer that must divide n ? 
Options: a ) 3 , b ) 4 , c ) 6 , d ) 8 , e ) 9

Ex Output:

c