Which statement is true? Group of answer choicesDue to law of supply, the price elasticity of supply is always negative.Profit is maximised when demand is unit elastic.The cross-price elasticity of normal goods is always negative.When the law of demand holds, for normal goods, price elasticity of demand is positive.None of the other answers are correct.

The correct statement is: "Profit is maximised when demand is unit elastic."

Here's why:

1. "Due to law of supply, the price elasticity of supply is always negative." - This is incorrect. The law of supply states that as the price of a good increases, the quantity supplied also increases. Therefore, the price elasticity of supply is positive, not negative.

2. "Profit is maximised when demand is unit elastic." - This is correct. When demand is unit elastic, it means that the percentage change in quantity demanded is exactly equal to the percentage change in price. This is the point where firms can maximise their total revenue, and hence their profit.

3. "The cross-price elasticity of normal goods is always negative." - This is incorrect. The cross-price elasticity of normal goods is positive if the goods are substitutes (i.e., if the price of one good increases, the demand for the other good also increases) and negative if the goods are complements (i.e., if the price of one good increases, the demand for the other good decreases).

4. "When the law of demand holds, for normal goods, price elasticity of demand is positive." - This is incorrect. The law of demand states that as the price of a good increases, the quantity demanded decreases. Therefore, the price elasticity of demand is negative, not positive.

5. "None of the other answers are correct." - This is incorrect because the statement "Profit is maximised when demand is unit elastic." is correct.