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'.

Input: Consider Input: Problem: a train is 485 meter long is running at a speed of 45 km / hour . in what time will it pass a bridge of 140 meter length 
Options: a ) 20 seconds , b ) 30 seconds , c ) 40 seconds , d ) 50 seconds , e ) none of these

Output: d


Input: Consider Input: Problem: a and b finish the job in 15 days . while a , b and c can finish it in 11 days . c alone will finish the job in 
Options: a ) 41.25 days , b ) 30.25 days , c ) 60.25 days , d ) 71.25 days , e ) 51.25 days

Output: a


Input: Consider Input: Problem: in one hour , a boat goes 13 km along the stream and 9 km against the stream . the speed of the boat in still water ( in km / hr ) is : 
Options: a ) 3 , b ) 5 , c ) 11 , d ) 9 , e ) 10


Output: c