In 2007, the price of oil increased, which in turn caused the price of natural gas to rise. This can best be explained by saying that oil and natural gas are: Complements and the higher price for oil increased the demand for natural gas. Complements and the higher price for oil decreased the supply of natural gas. c. Substitutes and the higher price for oil increased the demand for natural gas. Substitutes and the higher price for oil decreased the supply of natural gas. Unrelated and the prices of both products increased because of increased reliance on fossil fuels e. A leftward shift in the supply curve might be caused by: An improvement in production technology A decline in the prices of resources used in production An increase in consumer incomes. Some firms leaving the industry All of the above. b. C. e. If the quantity supplied of a product is less than its quantity demanded, then a. There is a shortage and the price of the product will fall b. There is a surplus and the price of the product will fall C. d. There will be less advertising and the price of the product will fall e. None of the above There will be more advertising and the price of the product will rise Suppose that tacos and pizza are substitutes, and that soda and pizza are complements. We would expect an increase in the price of pizza to Reduce the demand for tacos and increase the demand for soda. Reduce the demand for soda and increase the demand for tacos c. Increase the demands for both soda and tacos. Reduce the demands for both soda and tacos. Have no effect on the demands of tacos and soda e.