Answer:
Supply side is the view point of the Firms or the Businesses.
Explanation:
As the law of demand deals with the consumers side, the law of supply deals with the suppliers or the firms/businesses.
this tries to explain the factors that affect the supply, such as the prices of the substitutes and complements, the price of a commodity itself, taxes, government subsidies, technological influences, etc...
in this question, the 1st option, consumer is wrong. However, in certain situations, Government can be acted as a "supplier" (if there is a government monopoly on the supply of a good or a service", and government is a heavy influencer of supply through the implementaion of taxes and subsidies!