Read this excerpt:

Since the beginning of our American history, we have been engaged in change in a perpetual peaceful revolution a revolution which goes on steadily, quietly adjusting itself to changing conditions without the concentration camp or the quick-lime in the ditch. The world order which we seek is the cooperation of free countries, working together in a friendly, civilized society.

Franklin D. Roosevelt, "Four Freedoms Speech: Annual Message to Congress on the State of the Union," January 6, 1941

This excerpt from Roosevelt's Four Freedoms speech best relates to which common American theme?

A. Americans are hardworking.
B. Americans have strong morals.
C. Americans are good fighters.
D. Americans will help win this war.

Explanation: in the given excerpt from Franklin D. Roosevelt's "Four Freedoms Speech" we can see the description of how American history has been in constant change by the development of a peaceful revolution that has adjusted itself to the changing conditions. From the given options the one that best represents the theme expressed in the excerpt is the corresponding to option B: Americans have strong morals, we can see that specially in the last sentence "The world order which we seek is the cooperation of free countries, working together in a friendly, civilized society."