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'.

Example Input: Problem: two trains are running in opposite directions in the same speed . the length of each train is 120 meter . if they cross each other in 12 seconds , the speed of each train ( in km / hr ) is 
Options: a ) 30 km / hr , b ) 36 km / hr , c ) 80 km / hr , d ) 90 km / hr , e ) none of these
Example Output: b

Example Input: Problem: a train running at the speed of 60 km / hr crosses a pole in 6 sec . what is the length of the train ? 
Options: a ) 356 , b ) 278 , c ) 127 , d ) 100 , e ) 150
Example Output: d

Example Input: Problem: a train 110 m long is running with a speed of 30 km / hr . in what time will it pass a man who is running at 6 km / hr in the direction opposite to that in which the train is going ? 
Options: a ) 7 sec , b ) 6 sec , c ) 8 sec , d ) 11 sec , e ) 2 sec
Example Output:
d