Why does the entry of firms into an industry decrease the economic profits of the existing firms? Why does the exit of firms from an industry increase the economic profits of the existing firms?

 the economy goes into a recession, we can expect: 

A. An increase in the supply of goods, lower prices, a decrease in the demand for labor and lower wages.

B An increase in the demand for goods, higher prices, an increase in the supply of labor and lower wages.

C. A decrease in the demand for goods, lower prices, a decrease in the demand for labor and lower wages.

D) A decrease in the supply of goods, higher prices, an increase in the demand for labor and higher wages.