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: a , b , k start from the same place and travel in the same direction at speeds of 30 km / hr , 40 km / hr , 80 km / hr respectively . b starts two hours after a . if b and k overtake a at the same instant , how many hours after a did k start ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 5 , e ) 6

Ex Output:
d


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 16 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 ) 2887 , b ) 444 , c ) 877 , d ) 278 , e ) 178

Ex Output:
b


Ex Input:
Problem: the radius of a wheel is 22.4 cm . what is the distance covered by the wheel in making 600 resolutions ? 
Options: a ) 844.8 m , b ) 704 m , c ) 774 m , d ) 714 m , e ) 744 m

Ex Output:

a