The correct answer is option 4, the 1970`s. This decade is known as the "Era of Decolonisation" because it was a time when many colonies gained independence from their colonial rulers. Throughout this decade, numerous countries in Africa and Asia were granted their independence, marking a significant shift in global politics and the elimination of colonial rule. The decolonization movement was driven by a combination of factors, including growing nationalist movements, pressure from the international community, and the decline of colonial powers after World War II. This period of decolonization led to the formation of new nations and reshaped the geopolitical landscape.