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'.

Ex 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

Ex Output:
c


Ex Input:
Problem: a cyclist bikes x distance at 20 miles per hour and returns over the same path at 16 miles per hour . what is the cyclist ' s average rate for the round trip in miles per hour ? 
Options: a ) 17.6 , b ) 17.3 , c ) 8.6 , d ) 17.2 , e ) 9.0

Ex Output:
a


Ex Input:
Problem: sides of a rectangular park are in the ratio 2 : 5 and its area is 3750 sq m , the cost of fencing it at 50 ps per meter is ? 
Options: a ) s . 122 , b ) s . 129 , c ) s . 125 , d ) s . 120 , e ) s . 130.64

Ex Output:

e