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'.

Input: Consider Input: Problem: a copy machine , working at a constant rate , makes 40 copies per minute . a second copy machine , working at a constant rate , makes 55 copies per minute . working together at their respective rates , how many copies do the two machines make in half an hour ? 
Options: a ) 90 , b ) 2,700 , c ) 4,500 , d ) 5,400 , e ) 2,850

Output: e


Input: Consider Input: Problem: if the horse can run 10 miles / hour , how many days would it take for a horse to run from new york city to washington . d . c . ? ( 240 miles from nyc to d . c . ) 
Options: a ) 0.6 , b ) 0.8 , c ) 1 , d ) 1.2 , e ) 1.4

Output: c


Input: Consider Input: Problem: in a manufacturing plant , it takes 36 machines 4 hours of continuous work to fill 4 standard orders . at this rate , how many hours of continuous work by 72 machines are required to fill 12 standard orders ? 
Options: a ) 3 , b ) 6 , c ) 8 , d ) 9 , e ) 12


Output: b