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

Ex Output:
d


Ex Input:
Problem: ( 700 + 200 ) ã — 4 ã — ( 4 + 2 ) = ? 
Options: a ) 24500 , b ) 21600 , c ) 36600 , d ) 22400 , e ) 12500

Ex Output:
b


Ex Input:
Problem: a student took 6 courses last year and received an average ( arithmetic mean ) grade of 100 points . the year before , the student took 5 courses and received an average grade of 40 points . to the nearest tenth of a point , what was the student ’ s average grade for the entire two - year period ? 
Options: a ) 79 , b ) 89 , c ) 95 , d ) 72.72 , e ) 97.2

Ex Output:

d