Final answer:
John Locke was the Enlightenment thinker whose ideas significantly influenced the American founders and the writing of the Declaration of Independence. The correct option is A.
Step-by-step explanation:
The Enlightenment thinker/writer who influenced the writers of the Declaration of Independence was John Locke. Locke's contributions to political and philosophical thought, as expressed in social contract theory and ideas about individual freedoms and government responsibility, strongly impacted the foundation of American revolutionary thought.
His ideas that a government should protect individual rights and freedoms and that sovereignty resides in the consent of the governed were key elements that resonated with the founders of the United States.