The correct answer is letter A.
Explanation: Tennis Court Oath was a symbolically time that the official representatives of the Third State (the broader social group of the Old Regime, including artisans, traders, and peasants) established an unbreakable alliance in the context of the Assembly of States-General.
Very abbreviated answer: The Black Death was another name for the plague, this claws caused by rats and lead to death of a large sum of the population.
Businesses compete in a free enterprise system because these systems exist in a capitalist environment, wherein the company with the "best idea" or product makes the sale and thus a profit--thus fostering competition.
The answer is that it has allowed cultures to spread quickly and easily from one country to another.