Answer:
A). Pledge their lives to one another.
Step-by-step explanation:
'Declaration of Independence' demonstrates the reasons why the colonies overthrew/broke away from their ruler(England) and established themselves as a prosper separate nation. It aims to display the idea that it becomes necessary('it becomes necessary for one people to dissolve the political bands') to dethrone the Government when it fails to provide basic human rights to its citizens.
At the end of the 'Declaration of Independence', the signers pledged their lives, honor, and fortunes to one another by dissolving 'British rule' and establishing themselves as an Independent state. Thus, option A is the correct answer.