tubac on Which audio encoding for the 4mp Dom w/audio?

Hi,

I have this camera with built in microphone:

4MP IP Network Prime Series Mini IR Vandal Dome with Audio
Product# IPVD-PR

In the setup menu of the camera's interface under audio, which encoding should I select?

G.722.1

G.711.ulan

G.711.alaw

MP 2L2

G.726

Thanks,

Tubac