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: 8 persons can build a wall 140 m long in 42 days . in how many days can 30 persons complete a similar wall 100 m long ? 
Options: a ) 12 , b ) 10 , c ) 8 , d ) 6 , e ) 5

Ex Output:
c


Ex Input:
Problem: a man can row upstream at 20 kmph and downstream at 60 kmph , and then find the speed of the man in still water ? 
Options: a ) 32 kmph , b ) 34 kmph , c ) 30 kmph , d ) 45 kmph , e ) 40 kmph

Ex Output:
e


Ex Input:
Problem: a train 110 m long is running with a speed of 30 km / h . in how many seconds will the train pass a man who is running at 3 km / h in the direction opposite to that in which the train is going ? 
Options: a ) 6 , b ) 8 , c ) 10 , d ) 12 , e ) 14

Ex Output:

d