Why are legal precedents, the english magna carta, and the writ of habeas corpus so important to law and government in new zealand?

a.
these represent a british legacy, which is important to the people of new zealand.
b.
because there is no written constitution, these to govern the nation and protect citizens.
c.
following these legal constructs makes new zealand different from australia, to whom they are often compared and from whom they wish to stand apart.
d.
the government is disorganized; these legal constructs represent the few political safeguards in the country.