Final answer:
The colonies were too far away for England to enforce its rule effectively.
Step-by-step explanation:
The factor that should be added to the list is option B: The colonies were too far away for England to enforce its rule effectively.
This factor is significant because the distance between England and the colonies made it challenging for the British government to enforce its laws and maintain control over the colonies. The colonists took advantage of this distance and developed their own systems of government and local officials, which gave them more political power than the royal officials appointed by England.
Furthermore, this distance also contributed to the colonists' sense of independence and, eventually, their desire for self-governance.
Learn more about Factors contributing to the political climate in the American colonies