What is the mandatory helmet requirement for motorcycle riders and their passengers under Ley 24.449?

1. Helmets are optional if speed is under 30 km/h in urban streets
2. Both the driver and passenger must wear an approved, standardized homologated helmet (casco homologado) properly strapped and fastened at all times
3. Helmets are required only on national routes during rain
4. Bicycle helmets may be substituted for motorcycle helmets