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: a house wife saved $ 2.50 in buying an item on sale . if she spent $ 25 for the item , approximately how much percent she saved in the transaction ?
Options: a ) 8 % , b ) 9 % , c ) 10 % , d ) 11 % , e ) 12 %

Ex Output:
b

Ex Input:
Problem: if a ' s salary is 20 % less than b ' s salary , by how much percent is b ' s salary more than a ' s ?
Options: a ) 5 % , b ) 10 % , c ) 15 % , d ) 25 % , e ) none

Ex Output:
d

Ex Input:
Problem: john was 22 years old when he married betty . they just celebrated their fifth wedding anniversary , and betty ' s age is now 7 / 9 of john ' s . how old is betty ?
Options: a ) 24 , b ) 26 , c ) 28 , d ) 21 , e ) 32

Ex Output:
d