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 is 485 meter long is running at a speed of 45 km / hour . in what time will it pass a bridge of 140 meter length 
Options: a ) 20 seconds , b ) 30 seconds , c ) 40 seconds , d ) 50 seconds , e ) none of these
Example Output: d

Example Input: Problem: 45 men took a dip in a water tank 40 m long and 20 m broad on a religious day . if the average displacement of water by a man is 4 m 3 , then the rise in the water level in the tank will be : 
Options: a ) 20 cm , b ) 25 cm , c ) 35 cm , d ) 50 cm , e ) none of these
Example Output: e

Example Input: Problem: a train running at the speed of 52 km / hr crosses a pole in 18 seconds . what is the length of the train ? 
Options: a ) 120 metres , b ) 180 metres , c ) 260 metres , d ) 150 metres , e ) 100 meters
Example Output:
c