Final answer:
In the long-run, aggregate production is primarily determined by the supply side, and in the short run, by the demand side of the economy, corresponding with the neoclassical and Keynesian economic theories respectively.
Step-by-step explanation:
In the long-run, aggregate production is determined by the supply side of the economy while in the short run it is determined by the demand. This concept is based on the understanding of neoclassical economists and Keynesian economists, where the former emphasizes Say's law (supply creates its own demand) for long-term economic focus, and the latter emphasizes Keynes' law (demand creates its own supply) for short-term economic focus.
The aggregate supply (AS) and aggregate demand (AD) model shows a vertical AS curve in the long run, representing an economy's potential output, and an upward-sloping SRAS curve in the short run, showing the positive relationship between the price level and the level of real GDP. Hence, the correct answer is Option 2: Supply; Demand.