Which phrase indicates that the colonists are protesting their lack of representation? "among [certain unalienable rights] are life, liberty, and the pursuit of happiness." "[governments derive] their just powers from the consent of the governed." "prudence [dictates] that governments—should not be changed for light and transient causes." "we hold these truths to be self-evident, that all men are created equal."

"Governments derive their just powers from the consent of the governed." 
They are saying here that governments should get their power from the people they are governing, rather than making decisions all on their own. The colonists were not being able to have any say in the British government and they felt like representation was a very important right of a citizen.
Hope this helps! Please let me know if I'm wrong. :)