Refer to the above diagram, which shows demand and supply conditions in the competitive market for product X. Other things equal, a shift of the supply curve from S₀ to S₁ might be caused by a(n):

government subsidy per unit of output paid to firms producing X.

increase in the number of firms producing X.

decline in the price of the basic raw material used in producing X.

increase in the wage rates paid to laborers employed in the production of X.