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'.

Example Input: Problem: the ration of the father ’ s age to his son ’ s age is 7 : 3 . the product of their ages is 756 . the ratio of their ages after 6 years will be : 
Options: a ) 5 : 2 , b ) 2 : 1 , c ) 11 : 7 , d ) 13 : 9 , e ) none of these
Example Output: b

Example Input: Problem: a , b and c have rs . 450 between them , a and c together have rs . 200 and b and c rs . 350 . how much does c have ? 
Options: a ) a ) 100 , b ) b ) 110 , c ) c ) 120 , d ) d ) 130 , e ) e ) 140
Example Output: a

Example Input: Problem: a special municipal payroll tax charges not tax on a payroll less than $ 300,000 and only 1 % on a company ’ s payroll above $ 300,000 . if belfried industries paid $ 200 in this special municipal payroll tax , then they must have had a payroll of ? 
Options: a ) $ 180,000 , b ) $ 202,000 , c ) $ 230,000 , d ) $ 400,000 , e ) $ 2 , 200,000
Example Output:
c