What document was a formal announcement of the colonies' break from great britain?

The correct answer is - Ghana, Nigeria, and South Africa.

The countries of Ghana, Nigeria, and the Republic of South Africa (RSA) all gained independence after the given year of 1945. They did not found it easy after their independence though and faced lots of problems, both internal and external, like Nigeria being overtaken by the military and ruled for full 3 years by it, the unrests in Ghana between the different ethnicities and deep economic crisis, racism in South Africa and also going into a long lasting war with Namibia and Angola.