Under 'Sessions and Startup' I have two tabs, 'General' and 'Advanced'.
Under 'General', there are tick boxes, as follows:
 Display chooser on login
 Automatically save session on logout
[tick] Prompt on logout
Under 'Advanced', there are tick boxes, as follows:
 Launch Gnome services on startup
 Launch KDE services on startup
 Manage remote applications
so, there's no 'Application Autostart' tab.
There's an 'Autostarted Applications' entry on the Settings menu, but that's just a list of autostarted applications.