A. By telling them Britain only cares about its own interests.
Explanation:
The first line of this excerpt of Thomas Paine's <em>Common Sense</em> gives us the answer where it says "her motive was interest not attachment". This is the first clue because it's telling us that Britain was looking out for her best interest. The passage continues explaining the ways in which Britain acted selfishly towards the colonists. Britain expected the colonists to fight on her behalf but was not willing to fight to protect them.
This is but one of the many points expressed in the document that Thomas Paine wrote that motivated many colonists to join the revolutionary effort. Even the title of the document <em>Common Sense</em> made a reference to the fact that Paine believed that it was simply common sense that the colonists should fight to replace the British government.
By telling them Britain cares only about its own interests.
Explanation:
The rationale: The correct answer summarizes the excerpt. It states that Paine believes Britain is only concerned about its own interests. Britain does have several enemies who may also consider the colonies to be an enemy, but that is not what the excerpt discusses.