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 200 m long is running with a speed of 68 kmph . in what time will it pass a man who is running at 8 kmph in the same direction in which the train is going ? 
Options: a ) 6 sec . , b ) 7 sec . , c ) 9 sec . , d ) 12 sec . , e ) none
Example Output: d

Example Input: Problem: along a yard 414 metres long , 24 trees are palnted at equal distances , one tree being at each end of the yard . what is the distance between two consecutive trees 
Options: a ) 18 , b ) 19 , c ) 10 , d ) 11 , e ) 12
Example Output: a

Example Input: Problem: two stations a and b are 20 km apart on a straight line . one train starts from a at 7 a . m . and travels towards b at 20 kmph . another train starts from b at 8 a . m . and travels towards a at a speed of 25 kmph . at what time will they meet ? 
Options: a ) 9 , b ) 10 , c ) 11 , d ) 12 , e ) 8
Example Output:
e