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: 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

Ex Output:
b


Ex Input:
Problem: a train 280 m long , running with a speed of 72 km / hr will pass a tree in 
Options: a ) 14 sec , b ) 15 sec , c ) 16 sec , d ) 20 sec , e ) none

Ex Output:
a


Ex Input:
Problem: convert the 17 / 36 m / s into kilometers per hour ? 
Options: a ) 1.7 , b ) 1.5 , c ) 1.3 , d ) 1.1 , e ) 1.2

Ex Output:

a