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 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

Example Input: Problem: there were 35 students in a hostel . due to the admission of 7 new students , he expenses of the mess were increased by rs . 42 per day while the average expenditure per head diminished by rs 1 . what was the original expenditure of the mess ? 
Options: a ) 125 , b ) 321 , c ) 561 , d ) 852 , e ) 420
Example Output: e

Example Input: Problem: 2 : 3 : : 23 : ? 
Options: a ) 25 , b ) 28 , c ) 22 , d ) 29 , e ) 30
Example Output:
d