Which of the 4 methods were used to adopt the constitution?

The U.S. Constitution was adopted through a combination of methods, primarily by the Convention method and state ratification conventions. The Constitution was drafted during the Constitutional Convention in 1787 and then sent to the states for ratification. Each state held its own convention to debate and vote on the document, ultimately leading to its adoption upon receiving the approval of nine states. This process highlighted the balance between federal and state authority and the importance of popular consent.