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 bus 75 m long is running with a speed of 21 km / hr . in what time will it pass a woman who is walking at 3 km / hr in the direction opposite to that in which the bus is going ?
Options: a ) 5.75 , b ) 7.62 , c ) 11.25 , d ) 4.25 , e ) 3.25
Example Output: c

Example Input: Problem: in what time will a railway train 110 m long moving at the rate of 36 kmph pass a telegraph post on its way ?
Options: a ) 6 sec , b ) 7 sec , c ) 8 sec , d ) 11 sec , e ) 2 sec
Example Output: d

Example Input: Problem: a train covers a distance of 20 km in 30 min . if it takes 18 sec to pass a telegraph post , then the length of the train is ?
Options: a ) 298 m , b ) 125 m , c ) 120 m , d ) 217 m , e ) 200 m
Example Output:
e