Guild Wars 2

If you do a personal story mission that ends with a choice to make (missions branching out) and the instance owner picks option 1, will other party members also get the option to choose?
If not, what happens if there are multi-race parties and the instance owner picks a lesser race to befriend that isn’t available to others?

If you’re on the same story step, the instance leader will always progress their story. Any other person on that story step can choose to have the choices go to theirs as well, thus progressing the story, or denying the choice and thus just going along for the ride. So if you’re on the step you choose a lesser race, you probably won’t be able to choose to share the options.