In a four-point strap tie-down system, the front and rear straps should be anchored so that the straps form approximately what angle to the floor for optimal securement?

1. Both front and rear straps at 90 degrees (vertical)
2. Front straps near 40-60 degrees and rear straps near 30-45 degrees to the horizontal
3. All straps lying flat at 0 degrees
4. Straps crossed directly under the seat