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 average of first seven prime numbers which are between 30 and 70 is 
Options: a ) 35.4 , b ) 42 , c ) 44.4 , d ) 57 , e ) 67
Example Output: c

Example Input: Problem: if the average of 5 positive integers is 70 and the difference between the largest and the smallest of these 5 numbers is 10 , what is the maximum value possible for the largest of these 5 integers ? 
Options: a ) 50 , b ) 52 , c ) 69 , d ) 78 , e ) 84
Example Output: d

Example Input: Problem: drum x is 1 / 2 full of oil and drum y , which has twice the capacity of drum x , is 1 / 3 full of oil . if all of the oil in drum x is poured into drum y , then drum y will be filled to what capacity ? 
Options: a ) 2 / 3 , b ) 5 / 6 , c ) 7 / 12 , d ) 11 / 12 , e ) 17 / 24
Example Output:
c