In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: convert 500 miles into meters ? 
Options: a ) 784596 , b ) 845796 , c ) 804670 , d ) 784596 , e ) 864520

Ex Output:
c


Ex Input:
Problem: two passenger trains start at the same hour in the day from two different stations and move towards each other at the rate of 24 kmph and 21 kmph respectively . when they meet , it is found that one train has traveled 60 km more than the other one . the distance between the two stations is ? 
Options: a ) 288 , b ) 540 , c ) 877 , d ) 278 , e ) 178

Ex Output:
b


Ex Input:
Problem: a car traveled 75 % of the way from town a to town b at an average speed of 50 miles per hour . the car travels at an average speed of s miles per hour for the remaining part of the trip . the average speed for the entire trip was 50 miles per hour . what is s ? 
Options: a ) 10 , b ) 20 , c ) 25 , d ) 30 , e ) 50

Ex Output:

e