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 car drives 90 miles on local roads at 30 mph , and 75 miles on the highway at 60 mph , what is the average speed of the entire trip ? 
Options: a ) 36 mph , b ) 40 mph , c ) 39 mph , d ) 42 mph , e ) 38 mph
Example Output: c

Example Input: Problem: if it takes 4 identical printing presses exactly 6 hours to print 8000 newspapers , how long would it take 2 of these presses to print 6000 newspapers ? 
Options: a ) 5 hrs , b ) 7 hrs , c ) 8 hrs , d ) 9 hrs 50 mins , e ) 9 hrs
Example Output: e

Example Input: Problem: 16 boys or 24 girls can construct the wall in 6 days . the number of days that 8 boys and 24 girls will take to construct ? 
Options: a ) 4 days , b ) 14 days , c ) 6 days , d ) 8 days , e ) 9 days
Example Output:
a