Unfortunately Audition CS6 didn't support WASAPI. Later versions do. But I would have thought that there should be other settings for recording in the Windows set up page. Try right clicking in the white empty space below the two listed options and tick the boxes to Show Disabled Devices and Show Disconnected Devices to make sure that other recording options haven't been hidden on your Windows installation. Then Audition should be able to use them via the MME drivers.