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 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

Ex Output:
c


Ex Input:
Problem: cole drove from home to work at an average speed of 60 kmh . he then returned home at an average speed of 90 kmh . if the round trip took a total of 2 hours , how many minutes did it take cole to drive to work ? 
Options: a ) 66 , b ) 70 , c ) 72 , d ) 75 , e ) 78

Ex Output:
c


Ex Input:
Problem: x can do a piece of work in 20 days . he works at it for 10 days and then y finished it in 12 days . how long will y take to complete the work ? 
Options: a ) 10 , b ) 12 , c ) 24 , d ) 29 , e ) 30

Ex Output:

c