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: 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 150 milliliters of solution x to create a solution that is 25 percent alcohol by volume ? 
Options: a ) 250 / 3 , b ) 500 / 3 , c ) 400 , d ) 450 , e ) 600

Ex Output:
d


Ex Input:
Problem: x + ( 1 / x ) = 1.5 find x ^ 2 + ( 1 / x ^ 2 ) 
Options: a ) 2.25 , b ) 3.25 , c ) 4.25 , d ) 5.25 , e ) 0.25

Ex Output:
e


Ex Input:
Problem: the mean proportional between 234 and 104 is 
Options: a ) 12 , b ) 39 , c ) 54 , d ) 156 , e ) none

Ex Output:

d