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: 20 beavers , working together in a constant pace , can build a dam in 18 hours . how many hours will it take 12 beavers that work at the same pace , to build the same dam ? 
Options: a ) 22 . , b ) 24 . , c ) 30 . , d ) 36 , e ) 38 .

Ex Output:
c


Ex Input:
Problem: hcf and lcm two numbers are 20 and 396 respectively . if one of the numbers is 36 , then the other number is ? 
Options: a ) 36 , b ) 66 , c ) 132 , d ) 264 , e ) 220

Ex Output:
e


Ex Input:
Problem: the pinedale bus line travels at an average speed of 60 km / h , and has stops every 5 minutes along its route . yahya wants to go from his house to the pinedale mall , which is 6 stops away . how far away , in kilometers , is pinedale mall away from yahya ' s house ? 
Options: a ) 20 km , b ) 30 km , c ) 40 km , d ) 50 km , e ) 60 km

Ex Output:

b