A passenger below 1.35m arrives without a child restraint for a PHC booking. What is the safest regulatory response?

1. Proceed without restraint because PHCs are exempt from all child-restraint rules
2. Ensure an appropriate child restraint or booster is used unless a valid exemption applies
3. Let the child sit on an adult's lap in the front seat
4. Ask the child to hold the seat belt away from the neck and proceed