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: two trains of equal lengths take 10 sec and 15 sec respectively to cross a telegraph post . if the length of each train be 200 m , in what time will they cross other travelling in opposite direction ? 
Options: a ) 17 sec , b ) 12 sec , c ) 16 sec , d ) 15 sec , e ) 20 sec
Example Output: e

Example Input: Problem: a horse chases a pony 8 hours after the pony runs . horse takes 12 hours to reach the pony . if the average speed of the horse is 320 kmph , what s the average speed of the pony ? 
Options: a ) 182 kmph , b ) 192 kmph , c ) 193 kmph , d ) 196 kmph , e ) 190 kmph
Example Output: b

Example Input: Problem: in what time will a train 50 m long cross an electric pole , it its speed be 144 km / hr ? 
Options: a ) 1.25 sec , b ) 2.75 sec , c ) 3.5 sec , d ) 2.39 sec , e ) 9.5 sec
Example Output:
a