Answer:
It is estimated that by the early 16th century as much as 10% of Lisbon's population was of African descent. After the European discovery of the American continent, the demand for African labour gradually grew, as other sources of labour - both European and American - were found to be insufficient.
B. <span>a shield of missiles over the U.S. designed to shoot down incoming nuclear missiles from the USSR</span>
C is your answer it let communist countries under the USSR to transition over to Capitalism
B. a country is harboring terrorists responsible for attacks on the U.S.
Explanation:
The Powell Doctrine is a term that is used for a policy that is primarily focused on defense of the country and preventing attacks on the country, usually by using military force. In order for a military attack to be approved though numerous things have to be taken in consideration, examined, and answered.
From the presented scenarios, the Powell Doctrine would enable the U.S. the intervene in a country is harboring terrorists responsible for attacks on the U.S. Such examples in the past few decades have been the war in Afghanistan because of Al-Qaeda, and the war in Iraq, also because of Al-Qaeda. A military intervention also occurred in Iraq and the neighboring Syria because of the rise of the terrorist organization ISIS among other reasons.