Suppose the market demand curve for apples is a downward-sloping line with constant slope equal to -1. Which of the following statements is correct? Own-price elasticity of demand is "unitary" everywhere along this demand curve. If the price of apples increases by 10%, the quantity demanded of apples always decreases by 10%. O If the price of apples changes, consumer expenditure on apples always remains unchanged. There is one point on this market demand curve where own-price elasticity equals -1. O Each of the preceding statements is correct