Which of the following markets has a barrier to entry? A. Gold can only be mined in certain places in the world. B. There are already many fast food restaurants in the City of Buffalo. C. Stan's Garbage Company runs the only trash collection service in town. D.An aluminum company owns all bauxite mines comma an essential input. An aluminum company owns all bauxite mines comma an essential input.An aluminum company owns all bauxite mines, an essential input