What document guaranteed a representative assembly elected by landowners in Pennsylvania?

The correct answer is the Frame of Government. This foundational document, established by William Penn in 1682, created a framework for the governance of Pennsylvania and specifically outlined provisions for a representative assembly. Under this system, landowners were granted the right to elect representatives, thus ensuring that the government reflected the interests of those who held property. This structure was significant for its time, as it allowed for a degree of self-governance and participation in the political process among landowning citizens.

The Charter of Liberties, while also related to Pennsylvania's governance, was a later document that further expanded certain rights and liberties but did not specifically establish a representative assembly elected by landowners. The Articles of Confederation and the Constitution of 1789 pertain to broader frameworks of governance for the United States as a whole and are not specific to Pennsylvania's representative assembly structure.