As the Number of Firms Change in an Oligopoly Market,what

As the number of firms change in an oligopoly market,what will it become

A) As the number of firms decreases, the market approaches a cartel equilibrium.
B) As the number of firms decreases, the market approaches a socially optimal equilibrium.
C) As the number of firms increases, the market approaches a competitive market equilibrium.
D) As the number of firms increases, the market approaches a monopoly market equilibrium.