Final answer:
The Quebec Act of 1774 extended the boundaries of Quebec into the Ohio Valley, which was a significant territorial change at the time.
Step-by-step explanation:
The legislation known as the Quebec Act of 1774 had several provisions, one of which was particularly significant in terms of territorial changes. The correct answer to the question posed about the Quebec Act is that the boundaries of Quebec were extended into the Ohio Valley. This provision greatly enlarged the territory of Quebec and was of considerable concern to the American colonists, as it impinged on land claims made by several colonies.