Task: Question Answering
Input (English): Problem: a can do a piece of work in 6 days . b can do it in 6 days . with the assistance of c they completed the work in 2 days . find in how many days can c alone do it ? 
Options: a ) 8 days , b ) 2 days , c ) 6 days , d ) 7 days , e ) 4 days
Output (English): c