Answer:
The correct answer is D. In the early 19th century, many Europeans felt that Americans lacked of a strong national identity.
Step-by-step explanation:
American roots can be traced back to the British colonies that were founded by the Kingdom of England at the beginning of the 17th century. In 1776, independence was declared and then the War of Independence broke out and ended in 1783. Five years later, the US Constitution was ratified.
That is, in the 19th century the United States was a young nation, with many differences among its inhabitants (even reaching a Civil War), so that in the eyes of Europeans, who came from nations with centuries of antiquity and history, Americans lacked a strong national identity.