Which of the following is not a characteristic of a competitive market ?

Which of the following is not a characteristic of a competitive market ?

A. All of these answers are characteristic of a competitive market
B. The are many buyers and sellers in the market
C. The goods offered for sale are largely the same.
D. Firms generate small but positive economic profits in the long run
E. Firms can freely enter or exit the market

Holding all factors constant except one and increasing a variable factor is expected to lead to steadily decreased marginal product of that factor, this is an example of ?

Holding all factors constant except one and increasing a variable factor is expected to lead to steadily decreased marginal product of that factor, this is an example of ?

A. decreasing returns to scale
B. The law of diminishing returns
C. constant returns to scale
D. an inefficient production technique