Answer:
An invasion, via blitzkrieg tactics.
Explanation:
A.) Poison Gas is the answer
The Battle of Lexington and Concord are seen as the start of the American Revolution.
These battles mark the first open hostilities with the British Army and signaled the beginning of the War and were seen as the opening of a divide between the British and its colony.
Pretty sure your answer is B. They didn't get equal rights until the 60's, I don't believe they were removed from jobs, and I'm fairly certain they wouldn't have done work without pay (The Great Migration is a good example of that).