Suppose an increase in the price of rubber coincides with an advance in the technology of tire production. As a result of these two events, the demand for tires a. is unaffected, and the supply of tires increases. b. is unaffected, and the supply of tires decreases. c. decreases, and the supply of tires increases. d. is unaffected, and the supply of tires could increase, decrease, or stay the same.