Demand for Traditional Fast-Food Providers Such as McDonald's, Burger King

Demand for traditional fast-food providers such as McDonald's, Burger King, and Wendy's has been on a decline in recent years. Consumers have become more health conscious and demand has shifted to alternative restaurants like Subway, Chick-fil-A, and Chipotle. Attempts by McDonald's and Wendy's to steal customers from one another include frequent discounting tactics such as dollar menus. Such competitive actions are indicative of

A) profitability increases.
B) perfect competition.
C) natural monopolies.
D) cutthroat competition.