单选题 A recipe for soda requires ω liters of water for every liter of syrup. If soda is made according to this recipe using rn liters of syrup, and sold for j dollars a litter, what will be the gross profit if syrup costs k dollars a liter and water costs nothing?
(A) m(ω+k)
(C) m(jω-k)
(D) (j-k)m
(E) jm(1+ω)-km