What do economies of scale,the ownership of essential raw materials,and patents have in common?

A) They must all be present before price discrimination can be practiced.
B) They are all barriers to entry.
C) They all help explain why a monopolist's demand and marginal revenue curves coincide.
D) They all help explain why the long-run average cost curve is U-shaped.

Economies of Scale

The cost advantages that enterprises obtain due to their scale of operation, with cost per unit of output decreasing with increasing scale.

Essential Raw Materials

Fundamental inputs necessary for the production of goods, often considered critical for a country's economy and security.

Patents

Legal rights granted by the government to inventors, giving them exclusive rights to their inventions for a certain period of time.