For the products A, B, C and D, which of the following could be a linear programming objective function?

For the products A, B, C and D, which of the following could be a linear programming objective function? A. Z = 1A + 2B + 3C + 4DB. Z = 1A + 2BC + 3DC. Z = 1A + 2AB + 3ABC + 4ABCDD. Z = 1A + 2B/C + 3DE. all of the above