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: ( 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 odd 3 - digit integers greater than 800 are there such that all their digits are different ? 
Options: a ) 40 , b ) 56 , c ) 72 , d ) 81 , e ) 104

Ex Output:
c


Ex Input:
Problem: the value of 3.6 x 0.48 x 2.50 / 0.12 x 0.09 x 0.5 is 
Options: a ) 80 , b ) 800 , c ) 8000 , d ) 80000 , e ) none of these

Ex Output:

b