Suppose that the federal government determines the total level of municipal sewage that can be discharged by cities along a river. If the cities are able to exchange rights to the total discharge level among themselves, then the government's environmental policy includes:

answer: d. characteristics of guests

explanation: it is directly related to the spending characteristics of attendees who fall into each of these categories:

staple goods and impulse goods are examples of convenience products which consumers usually  buy. these products can be bought almost everywhere and are readily available for purchase. usually, the quality and price of the product are not considered. examples of staple goods are sugar and bread, while impulse goods examples are chocolates and magazine.