On a motorway or main extra-urban road that requires an e-vignette, what must the Category B driver have?

1. A printed paper sticker in the old format, or the vehicle is always fined
2. A valid e-vignette; electronic evidence is accepted and there is no need to print it
3. Nothing; vignettes were abolished for Category B
4. A foreign motorway pass that replaces the Bulgarian vignette automatically