What is a reason that market prices are not always the same as equilibrium prices?

Market prices are often set by buyers rather than by sellers.

Supply and demand are not well-understood by business owners.

The equilibrium is not always the most profitable price point.

It is not always practical for businesses to change their prices on a daily basis in order to reflect the equilibrium price.

External factors such as government regulations, taxes, subsidies, and market shocks can also affect prices and prevent them from reaching equilibrium. Additionally, imperfect competition, such as monopolies or oligopolies, can distort prices away from the equilibrium level. Lastly, psychological factors, such as consumer behavior and perceptions, can also influence market prices and cause them to deviate from equilibrium.

so a,b,c,d

Yes, all of those reasons can contribute to market prices not always being the same as equilibrium prices.