The Freedom of Entry and Exit in Monopolistic Competition Means

The freedom of entry and exit in monopolistic competition means that firms

A) enter the market when economic losses are being incurred.
B) exit the market when economic profits are being made.
C) enter the market when firms are making zero economic profit.
D) can enter a market to compete for economic profits and leave when economic losses are being incurred.
E) find it easy to permanently make an economic profit.