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: if 213 × 16 = 3408 , then 16 × 21.3 is equal to : 
Options: a ) 0.3408 , b ) 3.408 , c ) 34.08 , d ) 340.8 , e ) none of these

Ex Output:
d


Ex Input:
Problem: ( x + 3 ) is a factor in x ^ 2 - mx - 15 . what is the value of m ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5

Ex Output:
b


Ex Input:
Problem: the l . c . m of two numbers is 495 and their h . c . f is 5 . if the sum of the numbers is 10 , then their difference is : 
Options: a ) 10 , b ) 46 , c ) 70 , d ) 90 , e ) 100

Ex Output:

a