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: 120 + 520 ÷ 5.00 = ? 
Options: a ) 100 , b ) 150 , c ) 120 , d ) 520 , e ) none
Example Output: 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 5000 as profit , what is their total profit ? 
Options: a ) 28000 , b ) 30000 , c ) 32000 , d ) 35000 , e ) none of these
Example Output: d

Example Input: Problem: a certain number when divided by 39 leaves a remainder 16 , what is the remainder when the same number is divided by 13 ? 
Options: a ) 7 , b ) 8 , c ) 9 , d ) 6 , e ) 3
Example Output:
e