Which of the Following Is True of a Constant Cost

Multiple Choice

Which of the following is true of a constant cost industry?

A) Along the industry's long-run supply curve,firms in the industry earn a positive economic profit.
B) The long-run supply curve for a constant cost industry is horizontal.
C) The industry's long-run supply curve is derived by horizontally summing the long-run supply curves of the individual firms.
D) In the long run,the industry experiences an increase in the price of inputs.