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: a & b started a partnership business . a ' s investment was thrice the investment of b and the period of his investment was two times the period of investments of b . if b received rs 4500 as profit , what is their total profit ? 
Options: a ) 28000 , b ) 30000 , c ) 31500 , d ) 34000 , e ) none of these
Example Output: c

Example Input: Problem: robert ate 13 chocolates , nickel ate 4 chocolates . how many more chocolates did robert ate than nickel ? 
Options: a ) a ) 4 , b ) b ) 7 , c ) c ) 9 , d ) d ) 5 , e ) e ) 2
Example Output: c

Example Input: Problem: a company has 15 managers and 75 associates . the 15 managers have an average salary of $ 90,000 . the 75 associates have an average salary of $ 30,000 . what is the average salary for the company ? 
Options: a ) $ 35,000 , b ) $ 40,000 , c ) $ 55,000 , d ) $ 65,000 , e ) $ 75,000
Example Output:
b