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 man can row upstream at 5 kmph and downstream at 25 kmph , and then find the speed of the man in still water ?
Options: a ) 15 , b ) 77 , c ) 30 , d ) 88 , e ) 34

Ex Output:
a

Ex Input:
Problem: p can do a work in the same time in which q and r together can do it . if p and q work together , the work can be completed in 10 days . r alone needs 30 days to complete the same work . then q alone can do it in
Options: a ) 10 , b ) 22 , c ) 25 , d ) 27 , e ) 30

Ex Output:
e

Ex Input:
Problem: what is the length of a bridge ( in meters ) , which a train 166 meters long and travelling at 45 km / h can cross in 40 seconds ?
Options: a ) 310 , b ) 318 , c ) 326 , d ) 334 , e ) 342

Ex Output:
d