Task: Question Answering
Input (English): Problem: a can do a piece of work in 4 hours . a and c together can do it in just 2 hours , while b and c together need 3 hours to finish the same work . in how many hours b can complete the work ? 
Options: a ) 10 hours , b ) 12 hours , c ) 16 hours , d ) 18 hours , e ) 20 hours
Output (English): b