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: 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: solution x is 10 percent alcohol by volume , and solution y is 30 percent alcohol by volume . how many milliliters of solution y must be added to 250 milliliters of solution x to create a solution that is 25 percent alcohol by volume ? 
Options: a ) 250 / 3 , b ) 750 , c ) 400 , d ) 480 , e ) 600
Example Output: b

Example Input: Problem: the largest natural number which exactly divides the product of any 4 consecutive natural numbers is 
Options: a ) 6 , b ) 12 , c ) 24 , d ) 120 , e ) none
Example Output:
c