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'.

Example Input: Problem: a house wife saved $ 3.50 in buying an item on sale . if she spent $ 32.50 for the item , approximately how much percent she saved in the transaction ? 
Options: a ) 8 % , b ) 9 % , c ) 10 % , d ) 11 % , e ) 12 %
Example Output: c

Example Input: Problem: the sum of all the integers k such that – 25 < k < 24 is 
Options: a ) 0 , b ) - 2 , c ) - 25 , d ) - 49 , e ) - 47
Example Output: e

Example Input: Problem: how many even integers n , such that 20 < = n < = 180 are of the form 3 k + 4 , where k is any natural number ? 
Options: a ) 24 , b ) 27 , c ) 30 , d ) 33 , e ) 36
Example Output:
b