17． A． racket B． rackets C． bat D． ball

Questions 17-20 are based on the following discussion about a survey result. What is the woman’s marketing strategies A: Target the 46 to 55 year-old age. B: Produce more athletic shoes. C: Sell tennis rackets. D: Hake people more health conscious.

Which of the following would lead to a DECREASE in the demand for tennis balls? A: A decrease in the price of tennis rackets B: An increase in the cost of producing tennis balls C: A decrease in average household income when tennis balls are a normal good D: An increase in the price of tennis balls E: None of the above