What does a circular sign with a red border showing two cars side by side (left car red, right car black) signify (Znak II-32, 'Zabrana preticanja')?

1. Overtaking of motor vehicles other than single-track mopeds and solo motorcycles is prohibited (Zabrana preticanja)
2. Motorcycles are prohibited from riding in the left lane
3. Mandatory formation of two parallel lanes for all vehicles
4. Road reserved exclusively for two-door passenger cars