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 searchlight on top of the watchtower makes 4 revolutions per minute . what is the probability that a man appearing near the tower will stay in the dark for at least 12 seconds ? 
Options: a ) 1 / 2 , b ) 2 / 3 , c ) 1 / 3 , d ) 1 / 4 , e ) 1 / 5

Ex Output:
e


Ex Input:
Problem: it is currently 7 : 05 pm . what time was it in the morning exactly 51,132 minutes ago ? 
Options: a ) 6 : 53 , b ) 6 : 55 , c ) 6 : 59 , d ) 7 : 03 , e ) 7 : 09

Ex Output:
a


Ex Input:
Problem: a train 250 meters long completely crosses a 300 meters long bridge in 45 seconds . what is the speed of the train is ? 
Options: a ) 32 , b ) 28 , c ) 29 , d ) 44 , e ) 21

Ex Output:

d