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: in a group of ducks and cows , the total number of legs are 36 more than twice the number of heads . find the total number of cows . 
Options: a ) 12 , b ) 14 , c ) 16 , d ) 18 , e ) 20
Example Output: d

Example Input: Problem: the average monthly income of p and q is rs . 2050 . the average monthly income of q and r is rs . 5250 and the average monthly income of p and r is rs . 6200 . the monthly income ofq is : 
Options: a ) 1100 , b ) 2100 , c ) 1200 , d ) 3100 , e ) 1300
Example Output: a

Example Input: Problem: the average of 6 no . ' s is 5.40 . the average of 2 of them is 5.2 , while the average of the other 2 is 5.80 . what is the average of the remaining 2 no ' s ? 
Options: a ) 5.2 , b ) 2.6 , c ) 3.6 , d ) 4.5 , e ) 4.6
Example Output:
a