The correct answer is A. were not completely unified.
B is not correct because they don't need to read a pamphlet to decide that something is wrong and should be changed. C is incorrect because they definitely did have reason to fight - they wanted their independence. D is incorrect because it would be stupid to wait for someone to give you an approval before you can start rebelling.
This leaves us with A as the correct answer - some colonists didn't want to separate from Britain, and some did.