Final answer:
The correct answer to which statement is a key idea in the Declaration of Independence is (b) The power of government comes from the people. This reflects the democratic principles that governments derive their powers from the consent of the governed and are established to secure the inalienable rights of the people.
Step-by-step explanation:
The key idea in the Declaration of Independence that is expressed by the statement given is that the power of government comes from the people. This concept is deeply rooted in democratic principles and is strongly influenced by the natural rights philosopher, John Locke. The Declaration particularly states that "Governments are instituted among Men, deriving their just powers from the consent of the governed." It underscores that when a government fails to protect the inalienable rights of life, liberty, and the pursuit of happiness, the people have the right, even the duty, to alter or abolish it and institute a new government that serves their safety and happiness. Therefore, the correct answer to the student's question would be (b) The power of government comes from the people.