What is the safety rule regarding children under 3 years of age traveling in an Austrian touring coach (Class III) equipped with safety belts?

1. Children under 3 years may be held on an adult's lap without any restraint, or secured in an appropriate child restraint system (ECE R44/R129) suited to their size and weight on a dedicated seat
2. Children under 3 must always occupy a separate seat with an adult three-point belt
3. Children under 3 must be strapped directly with the adult 3-point belt together with the parent sharing the same belt
4. Children under 3 are legally prohibited from traveling in coaches