2 Each day a local dog shelter spends an average of 2 40 on food per dog The manager estimates the shelter s daily expenses assuming there is at least one dog in the shelter using the function E x 30 2 40x Which statements regarding the function E x are correct I x represents the number of dogs at the shelter per day II x represents the number of volunteers at the shelter per day III 30 represents the shelter s total expenses per day IV 30 represents the shelter s nonfood expenses per day 1 I and III 2 I and IV 3 II and III 4 II and IV