Correct answer (as you noted): B. Citizens must be allowed to overthrow a government that does not protect rights.
Explanation/details:
In writing the Declaration of Independence, Thomas Jefferson drew from the ideas of 17th century philosopher John Locke. Locke favored the idea of a "social contract." According to his view, a government's power to govern comes from the consent of the people themselves -- those who are to be governed. This was a change from the previous ideas of "divine right monarchy" -- that a king ruled because God appointed him to be the ruler.
Locke repudiated the views of divine right monarchy in his<em> First Treatise on Civil Government</em>. In his <em>Second Treatise on Civil Government</em>, Locke argued for the rights of the people to create their own governments according to their own desires and for the sake of protecting their own life, liberty, and property. Locke argued that the people always remain in charge, and asserted that the people have the power to change their government and remove government leaders if the government is not properly serving the needs and well-being of the people. The Declaration of Independence applied these ideas specifically to the situation between the American colonists and government by Britain that was not properly serving their needs.
After the opening section of the Declaration of Independence (from which your question quoted), Jefferson went on to provide a list of "facts to be submitted to a candid world." He listed grievances of the colonists which demonstrated that the British king had been seeking to establish "an absolute Tyranny over these States" (the colonial states which were declaring their independence). Because tyranny was standard operating procedure by the British monarchy, the colonists believed they were justified in establishing their independence from Britain.
