The place where what sellers are willing to sell for and buyers are willing to buy for is called equilibrium price. Therefore, the correct answer is option (c) equilibrium price.
a) Market price: This answer is partly correct because market price is the actual price at which a good or service is sold in the market. In a competitive market, the market price is usually close to the equilibrium price, which is the price at which buyers and sellers reach a balance.
b) Elastic price: This answer is wrong. Elasticity means how much buyers or sellers change their behaviour in response to changes in price. Although it's related to the determination of equilibrium price, it's not the same thing.
c) Equilibrium price: This answer is correct. Equilibrium price is the price at which supply and demand for a good or service are equal. It's the price at which buyers and sellers are happy to trade.
d) Paradox of value: This answer is wrong. The paradox of value is a concept that observes how some things that are essential, like water, have a low value, while some non-essential things, like diamonds, have a high value. It's interesting, but it's not directly related to equilibrium price.
e) Both a and c: This answer is partially correct. Market price and equilibrium price are related. In a competitive market, the market price is usually close to the equilibrium price, which is where supply and demand for a good or service are balanced.
f) None of the above: This answer is incorrect. The correct answer is c because equilibrium price is the price at which supply and demand for a good or service are equal, and it's the price at which buyers and sellers are happy to trade.
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Quick Note
Option (e) "both a and c" is partially correct because market price and equilibrium price are related concepts, but only Option (c) fully answers the question. Therefore, the most accurate answer to the question is Option (c) "equilibrium price".