Which source reflects the highest degree of authority on the subject of shale-oil deposits in North America?

A) an article in an encyclopedia
B) an article in a national newspaper
C) an article in a journal on geological research
D) an article in a journal on public policy

Shale-Oil Deposits

Underground formations containing a type of unconventional oil that is extracted through hydraulic fracturing or other methods.

Geological Research

The scientific study of the Earth, including its composition, structure, processes, and history.

Authority

The power or right to give orders, make decisions, and enforce obedience.