The correct answer is D. Sweezy.
The kinked demand curve model of oligopoly was developed by Paul Sweezy in 1939. It is a model of oligopoly that assumes that firms have a kink in their demand curve at the current price. This kink arises because firms are afraid of losing market share if they raise prices, but they are also afraid of losing profits if they lower prices. As a result, firms tend to keep prices stable, even in the face of changes in costs or demand.
Augustin Cournot was a French economist who developed the Cournot model of duopoly in 1838. This model assumes that firms are price-takers and that they compete by choosing their output levels. The Stackelberg model of oligopoly was developed by Heinrich von Stackelberg in 1934. This model assumes that firms are price-setters and that they compete by choosing their prices. The Edgeworth model of duopoly was developed by Francis Ysidro Edgeworth in 1897. This model assumes that firms are price-takers and that they compete by choosing their quantities.