How best to display a rankable list with a heading and submit button?

I'm designing an app where users can vote on a list of choices by ranking them in order. The voting screen needs to have:

  • The title of the vote
  • The list of choices
  • a button to submit the user's ranking.

What I've got now, as displayed in Chrome on an Android phone, is:

What I'm not sure about:

  • Indicating that the top is most preferred and the bottom is least preferred; I'm not sure if the text I'm currently using is sufficiently clear. If there's a more concise way of communicating that, I'd definitely like to use that.
  • The location of the submit button; I want to make sure it doesn't get mixed in with the ranking part of the screen. Right now, there's a 3em separation between the "Least preferred option!" text and the button.
  • Communicating that the choices can be reordered by drag-and-drop, though I think the drag handles on the left might be sufficient.

Any feedback on these concerns (or other parts of the design) is quite welcome.