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 120 m long running at 60 kmph crosses a platform in 20 sec . what is the length of the platform ? 
Options: a ) 213 , b ) 298 , c ) 350 , d ) 726 , e ) 267
Example Output: a

Example Input: Problem: a train of 25 carriages , each of 60 meters length , when an engine also of 60 meters length is running at a speed of 60 kmph . in what time will the train cross a bridge 1.0 km long ? 
Options: a ) 2.5 , b ) 3 , c ) 5 , d ) 7 , e ) 9
Example Output: a

Example Input: Problem: if the speed of a man is 51 km per hour , then what is the distance traveled by him in 30 seconds ? 
Options: a ) 275 m , b ) 360 m , c ) 375 m , d ) 425 m , e ) 440 m
Example Output:
d