In the Long-Run,firms in a Competitive Industry Earn Only a Normal

Multiple Choice

In the long-run,firms in a competitive industry earn only a normal rate of return because:

A) decreasing returns to scale causes per unit costs to rise.
B) input prices will rise in the long-run and eliminate abnormal profits.
C) entry of new firms will eliminate abnormal profits.
D) profit per unit declines in the long-run.