What is the purpose of a literature hierarchy?

A$.$ IFRS uses the literature hierarchy exclusively to make it easier to conduct accounting research. The hierarchy establishes the precedent of common sources.

B$.$ U$.$S$.$ GAAP uses the literature hierarchy exclusively to make it easier to conduct accounting research. The hierarchy establishes the precedent of common sources.

C$.$ The literature hierarchy makes it easier to conduct accounting research. The hierarchy establishes the authority of different sources of accounting literature under U$.$S$.$

GAAP and IFRS.

D$.$ The literature hierarchy makes it easier to conduct tax research. The hierarchy establishes the authority of different sources of tax cases.