Task: Question Answering
Input (English): Problem: a can finish a piece of work in 5 days . b can do it in 25 days . they work together for four days and then a goes away . in how many days will b finish the work ? 
Options: a ) 3 days , b ) 1 day , c ) 2 days , d ) 4 days , e ) 5 days
Output (English): b