Create a new file called creditsScreen.lua and import Composer, the composer.newScene() function, and the backgroundImage variable:

local composer = require( "composer" )
local scene = composer.newScene()

local backgroundImage

Create the create() event. Add in the composer.removeScene("options") line, which will remove the "options" scene. This will occur after the player has transitioned from the options screen and is sent to the credits screen:

-- Called when the scene's view does not exist:
function scene:create( event )
  local sceneGroup = self.view

  -- completely remove options
  composer.removeScene( "options" )

  print( "\ncreditsScreen: create event" )
end

Add in the show() event and the backgroundImage display object:

-- Called immediately after scene...