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'.

Ex Input:
Problem: the sum of three consecutive even numbers multiples of 3 is 72 . what is the largest number ? 
Options: a ) 21 , b ) 24 , c ) 27 , d ) 36 , e ) none

Ex Output:
c


Ex Input:
Problem: working simultaneously and independently at an identical constant rate , 5 machines of a certain type can produce a total of x units of product p in 4 days . how many of these machines , working simultaneously and independently at this constant rate , can produce a total of 2 x units of product p in 2 days ? 
Options: a ) 11 , b ) 13 , c ) 15 , d ) 18 , e ) 20

Ex Output:
e


Ex Input:
Problem: what is the smallest integer t greater than 1 that leaves a remainder of 1 when divided by any of the integers 6 , 8 , and 10 ? 
Options: a ) 21 , b ) 41 , c ) t = 121 , d ) 241 , e ) 481

Ex Output:

c