Choices lead to whatever you want to lead, and then to whatever other choices you want to present within the parameters of your story. There’s no rule for that, one choice “a” could lead to five other choices and the choice “b” could only lead to two other choices, it depends on your story.
An advice though, you wouldn’t want to branch too much, as it becomes exponentially difficult to keep a mechanic like that. There’s a little bit more info that could help you here:
Or just searching “Branching” on the search bar would give you a lot of results that may have useful information too.