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 six to move away from the competing businesses
E. A meat packing plant discourages other companies from moving into the area