Under WA road rules, what must a rider do when road markings show a double continuous (unbroken) white centre line?

1. Cross the lines to overtake when no oncoming traffic is visible
2. Not cross the lines to overtake, but may cross to turn right, U-turn, or enter/leave a road
3. Never cross the lines under any circumstances
4. Cross the lines only if the adjacent lane is a broken-line lane