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 leak in the bottom of a tank can empty the full tank in 6 hours . an inlet pipe fills water at the rate of 4 liters per minute . when the tank is full in inlet is opened and due to the leak the tank is empties in 8 hours . the capacity of the tank is ? 
Options: a ) 5768 , b ) 5760 , c ) 5762 , d ) 5766 , e ) 5712
Example Output: b

Example Input: Problem: a train passes a station platform in 60 sec and a man standing on the platform in 20 sec . if the speed of the train is 54 km / hr . what is the length of the platform ? 
Options: a ) 615 m , b ) 420 m , c ) 168 m , d ) 197 m , e ) 691 m
Example Output: b

Example Input: Problem: excluding stoppages , the speed of a bus is 64 kmph and including stoppages , it is 50 kmph . for how many minutes does the bus stop per hour ? 
Options: a ) 15.5 , b ) 12.3 , c ) 10.5 , d ) 10.12 , e ) 13.12
Example Output:
e