Does anyone know if I can make a recording with Audacity with the settings below?
8000 Hz, 16-bit, Mono and the file type A/mu-Law Wave
The restriction is not likely to be the file format. Audacity doesn’t currently support Yosemite (OS-X 10.10).
But to answer you specifically, you would be recording in high quality format and converting to your file format afterward. The reason you would do that is mistakes. If you tried editing or production in 8000 sample rate, you would turn your show to trash immediately. Make your show or presentation perfect first and then downconvert it to a-Law, etc.
Koz
If you are asking how to make that conversion, someone gave you wrong information. *-Law is automatically 8-bit.
Tracks > Stereo Track to Mono if you already have a stereo recording.
After recording, change the project rate bottom right to 8000 Hz.
File > Export Audio… then choose “Other uncompressed files”. Click “Options…” . Choose WAV (Microsoft) header then either U-Law or A-Law encoding.
Set the project rate back to 44100 Hz for your next recording.
Gale