what is the name of the bengals quarterback?
(JOIN (R sports.sports_team_roster.player) (AND (JOIN sports.sports_team_roster.time_macro 2015^^http://www.w3.org/2001/XMLSchema#date) (AND (JOIN sports.sports_team_roster.position m.06b1q) (JOIN (R sports.sports_team.roster) m.01y49))))