Task: Question Answering
Input (English): Problem: you collect pens . suppose you start out with 5 . mike gives you another 20 pens . since her father makes pens , cindy decides to double your pens . since you ' re nice , you give sharon 19 pens . how many pens do you have at the end ? 
Options: a ) 39 , b ) 40 , c ) 31 , d ) 42 , e ) 43
Output (English): c