In an oligopolistic market, the 'Cournot Model' assumes that firms compete by simultaneously choosing their output quantities, while taking the output levels of their rivals as fixed and given.

Answer: True

Augustin Cournot's foundational model of oligopoly assumes that each firm decides how much to produce based on the assumption that its competitors will not change their current production levels. The market price is then determined by the total aggregate output of all firms. This strategic interdependence leads to a Nash Equilibrium where total output and price fall somewhere between the extremes of perfect competition and pure monopoly.