Converting AIFF 24bit to AIFF 16bit

I have some 24bit 96Khz audio tracks Id like to optimally downsample to 16bit 44.1. I understand I should apply dithering but don’t see the opportunity to select that in Audacity in the export audio dialog box. How do I correctly set this up. I have 10 tracks to convert, and ultimately Id like the result to be in 256Kbs AAC for use in iTunes.

thanks dan

Audacity applies dither by default when exporting, so you don’t need to do anything about that. Just export as 16-bit AIFF.
The sample rate of the exported file will be the same as the “Project Rate” (bottom left corner of the main Audacity window), so set that to 44100 before you export.