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: in a maths test , students were asked to find 5 / 16 of a certain number . one of the students by mistake found 5 / 6 th of that number and his answer was 200 more than the correct answer . find the number . 
Options: a ) 384 , b ) 76 , c ) 26 , d ) 28 , e ) 11

Ex Output:
a


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 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

Ex Output:
b


Ex Input:
Problem: cost is expressed by the formula tb ^ 4 . if b is doubled , the new cost r is what percent of the original cost ? 
Options: a ) r = 200 , b ) r = 600 , c ) r = 800 , d ) r = 1600 , e ) r = 50

Ex Output:

d