Final answer:
Market price is determined by competition, demand, and supply, but not by opportunity cost. Price ceilings and floors are set by governments and create excess demand or supply without shifting the demand or supply curves themselves.
Step-by-step explanation:
The market price is determined by all the following except opportunity cost. The primary determinants of market price are competition, demand, and supply. Opportunity cost refers to the next best alternative forgone when making a decision, and while it can influence individual decisions behind supply and demand, it does not directly determine market prices.
Price ceilings and price floors are tools used by governments to regulate the market. A price ceiling, set below the equilibrium price, is intended to keep prices affordable for consumers but does not directly shift demand or supply; instead, it can create shortages. A price floor, set above the equilibrium price, is used to prevent prices from falling too low but does not directly shift demand or supply; rather, it can lead to surpluses.
For illustration, a demand and supply diagram would show that neither a price ceiling nor a price floor shifts the demand or supply curve itself, but instead, they create areas of excess demand or excess supply at the regulated price levels.