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 length of minute hand of a clock is 5.4 cm . what is the area covered by this in 10 minutes
Options: a ) 15.27 , b ) 16.27 , c ) 17.27 , d ) 18.27 , e ) 19.27
Example Output: a

Example Input: Problem: two pipes a and b can separately fill a tank in 12 and 20 minutes respectively . a third pipe c can drain off 45 liters of water per minute . if all the pipes are opened , the tank can be filled in 15 minutes . what is the capacity of the tank ?
Options: a ) 542 , b ) 540 , c ) 675 , d ) 829 , e ) 279
Example Output: c

Example Input: Problem: a can run 256 metre in 28 seconds and b in 32 seconds . by what distance a beat b ?
Options: a ) 32 metre , b ) 28 metre , c ) 23 metre , d ) 15 metre , e ) 28 metre
Example Output:
a