Which of these is not a cause of desertification in the region?

What is the primary justification of the hypothesis that the early earth environment was void of oxygen? ( 2 points) data showing the concentrations of gases extracted from rocks fossil evidence regarding the origin of eukaryotes generally accepted atmospheric conditions molecular evidence based on evolutionary traits.

How would i answer this for an exam?

What did the native title act do? a. it recognized and protected aboriginal rights to land. b. it stated that aborigines were to be counted as part of the census. c. it established aboriginal languages as official. d. it granted aborigines suffrage.