Hi Deena,
By checking the awner option, Mendix stores the ID of the current logged-in user, who created the object,
so, 1. will be the correct answer,
Hope it helps!
The Administration.Account entity is a specialization of System.User, which means they will have the same ID. When creating a new object, Mendix will store the ID of the Account/User the user is signed in with, as owner.