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 passes a station platform in 35 sec and a man standing on the platform in 20 sec . if the speed of the train is 54 km / hr . what is the length of the platform ? 
Options: a ) 228 , b ) 240 , c ) 225 , d ) 166 , e ) 1811
Example Output: c

Example Input: Problem: the length of the bridge , which a train 130 meters long and travelling at 45 km / hr can cross in 30 seconds , is ? 
Options: a ) 288 , b ) 266 , c ) 245 , d ) 277 , e ) 211
Example Output: c

Example Input: Problem: in what time will a train 200 m long cross an electric pole , it its speed be 216 km / hr ? 
Options: a ) 2.5 sec , b ) 2.8 sec , c ) 8.5 sec , d ) 3.3 sec , e ) 4.5 sec
Example Output:
d