A supporting text may be
be
the opening paragraph of a case study.
the concluding paragraph of a case study.
a quote providing evidence in a case study.
set off in a different format than a case study.

it for the workers lik if you have a job thats what its for

explanation:

c or d both can be the answer

answer; andrew jackson approved nullification by signing it into law,and john calhoun opposed it saying it was unconstitutional;

a is the final : )