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 man started driving at a constant speed , from the site of a blast , the moment he heard the blast . he heard a second blast after a time of 30 mins and 25 seconds . if the second blast occurred exactly 30 mins after the first , how many meters was he from the site when he heard the second blast ? ( speed of sound = 330 m / s ) 
Options: a ) 8250 , b ) 9350 , c ) 10,450 , d ) 11,550 , e ) 12,650

Ex Output:
a


Ex Input:
Problem: a train running at the speed of 54 km / hr crosses a pole in 7 seconds . find the length of the train . 
Options: a ) 150 meter , b ) 105 meter , c ) 140 meter , d ) 135 meter , e ) none of these

Ex Output:
b


Ex Input:
Problem: the length of the bridge , which a train 130 m long and traveling at 45 km / hr can cross in 30 sec is ? 
Options: a ) 288 , b ) 269 , c ) 245 , d ) 888 , e ) 121

Ex Output:

c