A price floor is a minimum price set by the government or a regulatory body for a particular good or service, ensuring it cannot be sold below that price. Among the options provided, the correct example of a price floor is d) the minimum wage.
The minimum wage establishes a baseline for earnings that employers must pay their workers, preventing them from falling below a certain level. This is intended to protect workers from exploitation and ensure they receive a fair wage for their labor.
Option b) rent controlled apartments involves government intervention, but it tends to be a price ceiling rather than a floor, limiting how high rents can be charged. Options a) a sale price with a limit on the quantity you can purchase and c) predatory pricing, while related to pricing strategies, do not represent government-mandated minimum prices. Therefore, the minimum wage clearly exemplifies a price floor in economic terms.