Price elasticity as discussed in the textbook refers to: (choose all that apply) Select one or more: a. the change in the demand for a good in response to a change in income. b. the rate at which product prices vary in response to changes in customer demand. c. the range of production costs that change as a direct function of the availability of raw materials. d. the rate at which demand for a product or service fluctuates with price change. e. customers buy more of a product as they become cheaper.