Task: Question Answering
Input (English): Problem: 20 beavers , working together in a constant pace , can build a dam in 3 hours . how many b hours will it take 12 beavers that work at the same pace , to build the same dam ? 
Options: a ) 2 . , b ) 4 . , c ) b = 5 . , d ) b = 6 . , e ) b = 8 .
Output (English): c