Under what conditions are butter and margarine considered substitutes? When Question 15Select one: A. both butter and margarine are produced by the same company. B. both butter and margarine are spread on bread together. C. both butter and margarine are sold at the same store. D. a rise in the price of butter leads to an increase in the demand for margarine. E. a rise in the price of butter leads to a decrease in the demand for margarine