If long run aggregate supply (LRAS) is vertical, the statements that must be true is: Aggregate demand does not affect the quantity of output.
Aggregate supply can be defined as the amount of goods or product a firm is expected to produce and sell or made available to buyers at a particular period of time.
Hence, assuming aggregate supply is vertical, aggregate demand which is the amount of goods buyers are willing to buy will not not affect the quantity of output or goods produced.
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