The statement that best describes how non-Muslims fit into the social structure of the Ottoman Empire is: They were subjects who could govern their own communities.
In the Ottoman Empire, non-Muslim subjects, known as "dhimmis," were allowed to practice their own religions and govern their own communal affairs under the millet system. This system provided a degree of autonomy to various religious communities, allowing them to manage their own social, educational, and legal matters while still being subject to the overarching authority of the Ottoman state.