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: in what time will a train 140 meters long cross an electric pole , if its speed is 210 km / hr 
Options: a ) 5 seconds , b ) 4.5 seconds , c ) 3 seconds , d ) 2.4 seconds , e ) none of these

Ex Output:
d


Ex Input:
Problem: a train running at the speed of 120 km / hr crosses a pole in 18 seconds . what is the length of the train ? 
Options: a ) 560 , b ) 570 , c ) 580 , d ) 590 , e ) 600

Ex Output:
e


Ex Input:
Problem: two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively . if they cross each other in 26 seconds , what is the ratio of their speeds ? 
Options: a ) 1 : 3 , b ) 9 : 1 , c ) 2 : 3 , d ) 3 : 2 , e ) 3 : 4

Ex Output:

b