Which of the following best describes thw course of the mississippi river? a. crossing the most of the northern plains, this river flow across the rocky mountaines to dump ranges into the gulf of california. b. arising in the northern plains, this river flows through states between the appalachian and rocky mountain ranges and dumps into the gulf of mexico. c. crossing areas in over seven states, this river carves it's way across the western plains into northwestern mexico and the gulf beyond. d. arising in central florida, this river is one of two navigated and heavily traveled rivers in the world that flow north