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: a train 180 m long is running with a speed of 55 km / hr . in what time will it pass a man who is running at 7 km / hr in the direction opposite to that in which the train is going ? 
Options: a ) 5.5 , b ) 10.45 , c ) 7 , d ) 8 , e ) 9.5
Example Output: b

Example Input: Problem: cole drove from home to work at an average speed of 60 kmh . he then returned home at an average speed of 90 kmh . if the round trip took a total of 2 hours , how many minutes did it take cole to drive to work ? 
Options: a ) 66 , b ) 70 , c ) 72 , d ) 75 , e ) 78
Example Output: c

Example Input: Problem: a bus covered a distance of 250 km , partly at an average speed of 40 kmph and partly at 60 kmph . if the total time taken is 5.4 hours , then the distance covered at 40 kmph is 
Options: a ) 130 km , b ) 120 km , c ) 100 km , d ) 140 km , e ) 148
Example Output:
e