Witnesses?
Your question doesn't really have all the information necessary to have an accurate answer.
You didn't include the map, so I can't be entirely sure, but if it's the same test that I have, it's B.
Many events happened before loyalists left Boston and Philadelphia. Some major events were the Boston Massacre, Boston Tea Party, and some of the beginning battles of the Revolutionary War, like battle of Bunker Hill and Dorchester Heights. After Dorchester Heights, in Boston, many loyalists left when the British were kicked out. <span />
Answer:
Large-scale Mexican-U.S. migration has changed social, economic, and cultural life on both sides of the border. Migration to the United States can offer increased earnings and savings accumulation (Gathmann 2008).
I think it is "isolating themselves from other Asian Nations"?