Answer: B: The colonists believe that the British government has abused its power and, as a result, they have the right to split away and start their own government.
Explanation: "They too have been deaf to the voice of justice and of consanguinity." is referring to the British government and their harsh treatment of the colonies.
"We must, therefore, acquiesce in the necessity, which denounces our separation" is basically saying that because of the harsh treatment, the colonies have a right to separate from the British rule.