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: when greenville state university decided to move its fine arts collection to a new library , it had to package the collection in 20 - inch by 20 - inch by 15 - inch boxes . if the university pays $ 1.30 for every box , and if the university needs 3.06 million cubic inches to package the collection , what is the minimum amount the university must spend on boxes ?
Options: a ) $ 255 , b ) $ 275 , c ) $ 510 , d ) $ 1,250 , e ) $ 663

Ex Output:
e

Ex Input:
Problem: ( 51 + 52 + 53 + + 100 ) is equal to :
Options: a ) 2525 , b ) 2975 , c ) 3225 , d ) 3775 , e ) 3885

Ex Output:
d

Ex Input:
Problem: how many positive integers between 1 and 400 are there such that they are multiples of 25 ?
Options: a ) 12 , b ) 13 , c ) 16 , d ) 15 , e ) 11

Ex Output:
c