Task: Question Answering
Input (English): Problem: x can finish a work in 20 days . y can finish the same work in 16 days . y worked for 12 days and left the job . how many days does x alone need to finish the remaining work ? 
Options: a ) 2 , b ) 3 , c ) 9 , d ) 5 , e ) 8
Output (English): d