Definition: 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'.
Input: Problem: if sales tax is reduced from 5 % to 4 % , then what difference it will make if you purchase an item of rs . 1000 
Options: a ) 10 , b ) 20 , c ) 30 , d ) 40 , e ) 50
Output:
a