These principles: taxation only with representation, the right to trial, and due process of the law were contained in what?

Magna Carta

Explanation:

The Magna Carta is a document that bears the basic rules pointing out that every individual, including the king, is subject to the law of the land and the document also presented and guarantees rights to justice and the right to have a fair trial.  

The early citizens of the country see this document as one that clearly shows what liberty truly means and what the government should be doing around safeguarding the people and not to get them duly oppressed.

d. a week

hope this