Answer:economic activity within the physical borders of a country goods and services.
Explanation:
If I'm remembering correctly, the First Continental Congress was a few years after the Boston Massacre and was prompted by the Coercive Acts, so it isn't D.
The tea party was also in response to the Tea Act, among other frustrations, so I don't think the answer is B either.
I believe that A refers to the battle at Lexington and Concord in 1775, but some people think that the first "shots" were during the Boston Massacre in 1770, so it could be A, but I don't know if that "officially" started anything.
If it isn't A I would guess C
Textbooks normally frame the river valley civilizations as the first civilizations. As rivers were great sources of water, and generally created fertile arable land on the banks, these locations also allowed for goods and people to be transported more easily, and allowed for fishing and hunting of animals that came to drink. These early civilizations were known as hydraulic empires as they commanded the river and exerted control of access to the water sources within their governmental structures. These river valley civilizations were seen as the first and as the innovators for new technologies.
Americans worried because (A) any missile launched form Cuba could hit the U.S. within minutes.