Answer:
D. an increase in the number of sellers
Explanation:
In Economics, there are primarily two (2) factors which affect the availability and the price at which goods and services are sold or provided, these are demand and supply.
The law of demand states that, the higher the demand for goods and services, the higher the price it would be sold all things being equal. On the other hand, law of supply states that the higher the price of goods and services, the lower the supply.
Also, in order to understand both short-run economic fluctuations and how the economy move from short to long run, we need the aggregate supply and aggregate demand model.
Aggregate supply (AS) refers to the total quantity of output (goods and services) that firms are willing to produce and sell at a given price in an economy at a particular period of time.
An aggregate supply curve gives the relationship between the aggregate price level for goods or services and the quantity of aggregate output supplied in an economy at a specific period of time.
Hence, the factor that would cause the supply curve to shift to the right is an increase in the number of sellers because the quantity of aggregate output supplied to the market would increase i.e an increase in the quantity of goods supplied by the suppliers.