Light switches are on when they're in the down position.
This really depends on the part of the world you are living in.
When I was living in Central Europe the light switches were on when they were in the up position.
Edit: Even all my Canadian switches are like this. Up is on.
Especially annoying are the posh toggles, unnecessarily popular in some European countries (e.g. CH) that don’t have any physical indicator of on-off status.
Off: https://media.istockphoto.com/photos/light-switch-in-off-pos...
Also off: https://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Ro...
Unless you mean this kind that offer either way: https://m.media-amazon.com/images/I/71BTb1oUUYS.jpg
(B) The standard three way* switch would like a word.
* Which actually means two switches (or more).