What cause and effect relationship is described in this article? athe results of a study conducted by researchers at australia's charles darwin university caused researchers to begin tracking the fate of australia's land mammals since 1788. bthe colonization of seven species of land mammals on several australian islands has led to the decline of land mammals on those islands. cthe extinction of certain australian land mammals has caused a decline of virtually all species of land mammals on the continent. dthe introduction of two non-native species, along with widespread wildfires, brought about the decline of many of australia's small land mammals.