Final answer:
The Declaration of Independence, adopted on July 4, 1776, is the document that officially severed all ties between the American colonies and Great Britain, making it the correct answer to the student's question.
Step-by-step explanation:
The document that finally severed all ties between the American colonies and Great Britain was the Declaration of Independence. This historic document was adopted by the Second Continental Congress on July 4, 1776, and was primarily drafted by Thomas Jefferson. It included a list of grievances against King George III and laid out the colonies' right to be independent states, setting the foundation for the American government to be based on the consent of the governed.
The Olive Branch Petition was an earlier attempt at reconciliation, suggesting that the colonists be given free trade and fair taxation. However, after its rejection by King George III and his proclamation declaring the colonies in open rebellion, the path towards independence became more definitive. The movement was underscored by critical discussions and documents such as The Causes and Necessity of Taking Up Arms, which made clear the colonies' position and right to self-defense.