Ok, It is not A, becuase that is a feature of Common Law, it is not C, becuase C becuase that was under the Mabo Case, not D, becuase that was a british doctrine, the BEST answer is B - Dispute resolution.
Customary Law does not only refer to Aborigines, it refers to all customary laws whihc were customs used as proceedure to deal with disputes, even the Enlgish used these, and as it became more complex, courts were established.