Ranchers have changed the environment of the outback a.)mining for gold b.)drilling for oil and gas c.)cutting tree for lumber d.)drilling artesian wells

Ranchers have changed the environment of the outback by mining for gold.

Explanation:

The ranchers are in true sense into the profession of animal husbandry and herding cattle. But in the recent past, the ranchers of the outback have also been associated with the mining of gold to a great extent. The mining activities carried out by the ranchers at outback have stood responsible for the change in the local environment. The conventional means used by the ranchers for the mining of gold have proven perilous for the environment there.

Answer// dinosaurs emerged during mesozoic era;

How is this even a question?