Many Fast-Food Restaurants, Including Burger King, McDonald's, and Wendy's, No

Many fast-food restaurants, including Burger King, McDonald's, and Wendy's, no longer use polystyrene containers (which degrade very slowly in a landfill) for packaging their products. Rather, these firms wrap their burgers in recycled paper wrappers, containers, and bags, usually clearly marked as such. These fast-food restaurants are practicing

A) triple-top line marketing.
B) green marketing.
C) consumerism.
D) an ecological code of ethics.
E) cause marketing.