When was this oil first discovered?

The oil that flows from the kingdom of Saudi Arabia over decades employing a majority of working Saudis was first discovered by the Americans in 1938. The first striking of oil in commercial quantities at well No. 7 happened in Dammam,  in what is now modern-day Dhahran.

answer; /// i believe that the correct answer is (a) making presentations;

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.