Task: Pos Tagging
Input (English): Sentence: Now , FLDS leader Warren Jeffs has been added to the FBI 's list of " Ten Most Wanted Fugitives , " a move that caps law enforcement 's dramatic change of approach toward the polygamous group in recent years ... [ because of ] the impact that the group 's practices , law enforcement officials say , are having on the {{ most }} vulnerable within the sect , particularly children and women . 
Word: most
Output (English): RBS