Which of the following is an example of agglomeration?

A.) A steel mill is located in the country to take advantage of low labor costs.

B.) A clothing factory is located in the same city as a steel mill and a furniture factory.

C.) A coal mine is the only business employing workers in 20 miles in any direction.

D.) A paper mill seeks to move away from competing businesses.

E.) A meatpacking plant discourages other companies from moving into the area.