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: joe needs to paint all the airplane hangars at the airport , so he buys 360 gallons of paint to do the job . during the first week , he uses 1 / 4 of all the paint . during the second week , he uses 1 / 4 of the remaining paint . how many gallons of paint has joe used ? 
Options: a ) 18 , b ) 157 , c ) 175 , d ) 216 , e ) 250
Example Output: b

Example Input: Problem: buses a and b start from a common bus stop x . bus a begins to travel in a straight line away from bus b at a constant rate of 20 miles per hour . one hour later , bus b begins to travel in a straight line in the exact opposite direction at a constant rate of 80 miles per hour . if both buses travel indefinitely , what is the positive difference , in minutes , between the amount of time it takes bus b to cover the exact distance that bus a has covered and the amount of time it takes bus b to cover twice the distance that bus a has covered ? 
Options: a ) 36 , b ) 72 , c ) 132 , d ) 144 , e ) 180
Example Output: c

Example Input: Problem: if the wages of 6 men for 15 days be rs . 2100 , then find the wages of for 12 days . 
Options: a ) rs . 2420 , b ) rs . 2500 , c ) rs . 2520 , d ) rs . 2020 , e ) rs . 2650
Example Output:
c