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: a and b complete a work in 4 days . a alone can do it in 6 days . if both together can do the work in how many days ? 
Options: a ) 3.75 days , b ) 3.7 days , c ) 3.6 days , d ) 2.4 days , e ) 5.75 days

Ex Output:
d


Ex Input:
Problem: a company produces 72000 bottles of water everyday . if a case can hold 10 bottles of water . how many cases are required by the company to hold its one day production 
Options: a ) 2000 , b ) 4500 , c ) 5000 , d ) 7200 , e ) 9000

Ex Output:
d


Ex Input:
Problem: eddy and freddy start simultaneously from city a and they travel to city b and city c respectively . eddy takes 3 hours and freddy takes 3 hours to complete the journey . if the distance between city a and city b is 600 kms and city a and city c is 300 kms . what is the ratio of their average speed of travel ? ( eddy : freddy ) 
Options: a ) 2 / 1 , b ) 3 / 8 , c ) 8 / 5 , d ) 5 / 8 , e ) 5 / 3

Ex Output:

a