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'.

Example Input: Problem: calculate how many days it will take for 8 boys to paint a 50 m long wall if 6 boys can paint a 60 m long wall in 5 days , 
Options: a ) 4.13 days , b ) 3.13 days , c ) 513 days , d ) 9.13 days , e ) 2 days
Example Output: b

Example Input: Problem: a bus 75 m long is running with a speed of 21 km / hr . in what time will it pass a woman who is walking at 3 km / hr in the direction opposite to that in which the bus is going ? 
Options: a ) 5.75 , b ) 7.62 , c ) 11.25 , d ) 4.25 , e ) 3.25
Example Output: c

Example Input: Problem: amar takes as much time in running 18 meters as a car takes in covering 48 meters . what will be the distance covered by amar during the time the car covers 1.3 km ? 
Options: a ) 600 m , b ) 325 m , c ) 300 m , d ) 400 m , e ) 100 m
Example Output:
b