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: mary can do a piece of work in 28 days . rosy is 40 % more efficient than mary . the number of days taken by rosy to do the same piece of work is ? 
Options: a ) 22 , b ) 24 , c ) 20 , d ) 25 , e ) 27

Ex Output:
c


Ex Input:
Problem: a man rows his boat 75 km downstream and 45 km upstream , taking 2 1 / 2 hours each time . find the speed of the stream ? 
Options: a ) 6 , b ) 7 , c ) 5 , d ) 8 , e ) 9

Ex Output:
a


Ex Input:
Problem: when a train travels at a speed of 100 kmph , it reaches the destination on time . when the same train travels at a speed of 50 kmph , it reaches its destination 15 min late . what is the length of journey ? 
Options: a ) 15 km , b ) 50 km , c ) 60 km , d ) 85 km , e ) 95 km

Ex Output:

a