Answer:
B."For imposing Taxes on us without our Consent."
Step-by-step explanation:
This is the excerpt from the Declaration of Independence that best explains why the colonists were unhappy about their lack of representation in the British Parliament. In this excerpt, the colonists tell us that the king has imposed taxes on them without their consent. Consent is the most important element here, as the colonists were unable to give their consent due to their lack of representation.