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: car a is 30 miles behind car b , which is traveling in the same direction along the same route as car a . car a is traveling at a constant speed of 58 miles per hour and car bis traveling at a constant speed of 50 miles per hour . how many hours will it take for car a to overtake and drive 8 miles ahead of car b ?
Options: a ) 1.5 , b ) 4.5 , c ) 4.75 , d ) 3.75 , e ) 3.5

Ex Output:
c

Ex Input:
Problem: a and b can do a piece of work in 8 days . with the help of c they finish the work in 4 days . c alone can do that piece of work in ?
Options: a ) 40 days , b ) 20 days , c ) 8 days , d ) 60 days , e ) 40 days

Ex Output:
c

Ex Input:
Problem: a , b and c can complete a piece of work in 24 , 6 and 12 days respectively . working together , they will complete the same work in :
Options: a ) 33 / 7 , b ) 43 / 7 , c ) 24 / 7 , d ) 19 / 7 , e ) none

Ex Output:
c