Final answer:
The word B.)'Therefore' best completes the sentence, connecting King George III's belief that the Americans were seeking independence to the actions of the Second Continental Congress.
Step-by-step explanation:
The best word to complete the sentence ‘The American Revolution, 1763-1783 (excerpt). … in a speech to Parliament in October 1775, King George III said that the Americans were seeking independence.’ is Therefore. This signifies the consequence of the king’s proclamation and speech, which were essentially reactions to the colonists’ petition for redress of grievances and their subsequent loyalty assurances. It indicates a progression from the Second Continental Congress’s attempts at reconciliation to King George III’s refusal, which led to the realization that independence was the only viable option for the American colonies.