[AngelicaDeAlquezar]

I don't know if this is a regional use of the word "horario" (no accent), but this question is asking about a schedule, not the hour. My answer here would be 3).
In colloquial speech though, people may ask "¿Qué hora tienes?"

And no, you can't say "ocho". Even in a context when someone is asking you what time it is, "ocho" wouldn't be enough to say the hour. We need something that indicates that we are talking about the clock. The short form of "son las ocho", is "las ocho". However you can say "ocho y media" instead of "son las ocho y media", because "y media" indicates the hour, in the right context.