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: the speed of a boat in still water is 20 km / hr and the rate of current is 5 km / hr . the distance travelled downstream in 27 minutes is : 
Options: a ) 9.25 , b ) 5.25 , c ) 7.25 , d ) 6.25 , e ) 11.25
Example Output: e

Example Input: Problem: two trains , one from howrah to patna and the other from patna to howrah , start simultaneously . after they meet , the trains reach their destinations after 49 hours and 25 hours respectively . the ratio of their speeds is ? 
Options: a ) 4 : 9 , b ) 5 : 7 , c ) 4 : 5 , d ) 4 : 1 , e ) 4 : 2
Example Output: b

Example Input: Problem: a train traveling at 72 kmph crosses a platform in 30 seconds and a man standing on the platform in 19 seconds . what is the length of the platform in meters ? 
Options: a ) 220 meters , b ) 360 meters , c ) 420 meters , d ) 600 meters , e ) can not be determined
Example Output:
a