Task: Question Answering
Input (English): Problem: abel can complete a work in 8 days , ben in 12 days and carla in 15 days . all of them began the work together , but abel had to leave after 2 days and ben 3 days before the completion of the work . how long did the work last ? 
Options: a ) 4 , b ) 7 , c ) 8 , d ) 9 , e ) 10
Output (English): a