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: if a person walks at 14 km / hr instead of 10 km / hr , he would have walked 20 km more . the actual distance traveled by him is : 
Options: a ) 50 km , b ) 56 km , c ) 60 km , d ) 70 km , e ) 80 km
Example Output: a

Example Input: Problem: the average of 5 numbers is 27 . if one number is excluded the average become 25 . the excluded number is : 
Options: a ) 25 , b ) 27 , c ) 30 , d ) 35 , e ) 37
Example Output: d

Example Input: Problem: if ( 1 – 1.5 ) n = 1 , then n = 
Options: a ) − 400 , b ) − 140 , c ) − 2 , d ) 4 , e ) 400
Example Output:
c