<span>If the question is asking an overall approach to the Declaration of Independence, the first step has to be a mindset that asks "What was Jefferson saying." In doing so, the Preamble sets the rationale behind the move to independence and the "injuries and usurpations" the specifics. However, no matter what, an understanding of the historical context is imperative.
However, if the task is asking to break down each sentence in the Declaration and relate it to purpose, that would take a while here.</span>
Answer:
a day or period of celebration
typically for religious reasons
I think that C, that is, "they found the charge and trouble very great, and they had little or no crop it is not doubted", is your answer.
Understatement represents something as smaller or less intense than it reallly is, it presents it as less important. In sentence C, the speaker refers to a problem as a minor inconvinience "(...)trouble very great". Generarlly, we all know, that troubles are far from great. "They had little or no crop it is not doubted", you could change the focus and say that you have "some crop" instead of referring to the crop as being little.