Deadweight losses occur when the quantity of an output produced is: less than, but not when it is greater than, the competitive equilibrium quantity greater than, but not when it is less than, the competitive equilibrium quantity less than or greater than the competitive equilibrium quantity such that the marginal benefit of the output is just equal to the marginal cost

I think the correct answer would be the first option. Deadweight losses occur when the quantity of an output produced is less than, but not when it is greater than, the competitive equilibrium quantity. It is also known as allocative inefficiency. It is a loss of efficiency that will happen when the equilibrium of a good is not reached or the supply and the demand of a good are not in equilibrium such that the quantity of the goods is less than the equilibrium quantity. It is a loss due to inefficient use of the resources available. Price controls, minimum wage and taxation are said to cause deadweight loss.