Alan Montemayor, from left; Carye Bye; Gustavo Metzger, 12; Emmanuel Perez, 12; Isabel Perez, 12; and Luke Metzger hold signs Monday outside Whataburger’s San Antonio headquarters at 300 Concord Plaza. The group then delivered a petition signed by more than 50,000 people that originated with environmental groups Environment Texas, Surfrider Foundation’s Texas Coastal Bend Chapter and Care2.com. The petition asks Whataburger to stop its use of polystyrene foam (commonly known as Styrofoam) cups and containers at its restaurants.