Question

Economists usually call an industry an oligopoly if

A.there is one firm that produces 100 percent of the output

B.the ten largest firms produce less than 50 percent of the output

C.only one product is available on the market

D.the four largest firms produce at least 70-80 percent of the output​

Answer 1

D.the four largest firms produce at least 70-80 percent of the output

I already answered this on my test so i hope this helps!