The best answer that describes the most immediate impact of the Proclamation of 1763 on the British North American colonies is:
(Choice A) Colonists disobeyed the Proclamation of 1763, moving westward past the Appalachian Mountains.
The Proclamation was intended to stabilize relations with Native Americans by restricting colonial expansion westward, but many colonists ignored it and moved into the territory anyway. This act of defiance had significant implications for colonial relations with both the British government and Native populations.