Task: Question Answering
Input (English): Problem: brenda and sally run in opposite direction on a circular track , starting at diametrically opposite points . they first meet after brenda has run 100 meters . they next meet after sally has run 200 meters past their first meeting point . each girl runs at a constant speed . what is the length of the track in meters ? 
Options: a ) 250 , b ) 300 , c ) 350 , d ) 400 , e ) 500
Output (English): d