If an Innovation Lowers the Marginal Cost of Production for Firms

Multiple Choice

If an innovation lowers the marginal cost of production for firms in a competitive industry, then in the long run, the number of firms

A) increases and firms in the industry make normal profits.
B) does not change and firms in the industry make profits.
C) decreases and firms in the industry incur losses.
D) decreases and firms in the industry make profits.
E) decreases and firms in the industry make normal profits.