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: to fill a tank , 25 buckets of water is required . how many buckets of water will be required to fill the same tank if the capacity of the bucket is reduced to 3 / 10 of its present ? 
Options: a ) 61.5 , b ) 60.5 , c ) 63.5 , d ) 83.333 , e ) 64.5

Ex Output:
d


Ex Input:
Problem: a boat running downstream covers a distance of 12 km in 2 hours while for covering the same distance upstream , it takes 3 hours . what is the speed of the boat in still water ? 
Options: a ) 8 kmph , b ) 5 kmph , c ) 4 kmph , d ) 6 kmph , e ) 7 kmph

Ex Output:
b


Ex Input:
Problem: if a train , travelling at a speed of 360 kmph , crosses a pole in 5 sec , then the length of train is ? 
Options: a ) 381 m , b ) 112 m , c ) 500 m , d ) 125 m , e ) 433 m

Ex Output:

c