Under what conditions are butter and margarine considered substitutes? When Question 26Select one: A. both butter and margarine are spread on bread together. B. a rise in the price of butter leads to a decrease in the demand for margarine. C. a rise in the price of butter leads to an increase in the demand for margarine. D. both butter and margarine are sold at the same store. E. both butter and margarine are produced by the same company