What is the correct and safest riding posture for a pillion passenger on a motorcycle?

1. Sit astride the seat, keep feet on the footrests at all times, and hold the rider's waist or grab rails
2. Sit sideways (side-saddle) with both legs on one side of the motorcycle
3. Hold onto the rider's shoulders and lean in the opposite direction of turns
4. Keep feet dangling off the footrests to help balance in case of stops