Final answer:
The author's purpose in Common Sense was b. to convince the colonists to fight for independence.
Step-by-step explanation:
The author's purpose in Common Sense by Thomas Paine was b. to convince the colonists to fight for independence.
Paine wrote Common Sense to argue for the idea of independence from Great Britain and to convince the colonists of the need to fight for their freedom. He used simple and direct language to appeal to ordinary people and make his arguments accessible and persuasive.
By highlighting the failings of the British government and stressing the principles of natural rights and equality, Paine's pamphlet helped to rally support among the colonists for the cause of independence.