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 the radius of a cylinder is doubled and height 5 times , what is the new volume of the cylinder divided by the old one ? 
Options: a ) 8 . , b ) 2 . , c ) 6 . , d ) 20 . , e ) 10 .

Ex Output:
d


Ex Input:
Problem: a man is 20 years older than his son . in two years , his age will be twice the age of his son . the present age of the son is ? 
Options: a ) 11 , b ) 25 , c ) 27 , d ) 18 , e ) 91

Ex Output:
d


Ex Input:
Problem: a man purchased 1 blankets @ rs . 100 each , 5 blankets @ rs . 150 each and two blankets at a certain rate which is now slipped off from his memory . but he remembers that the average price of the blankets was rs . 150 . find the unknown rate of two blankets ? 
Options: a ) 278 , b ) 277 , c ) 278 , d ) 450 , e ) 650

Ex Output:

e