Who is widely regarded as the world's leading reserve auditor?

• A. BP
• B. Schlumberger
• C. Wood Mackenzie
• D. DeGoyler and MacNaughton

Answer: (D)

DeGolyer and MacNaughton are widely regarded as the world’s leading reserve auditor because they specialize in independent verification of oil and gas reserves, a role built on impartiality, rigorous methodology, and global reach. They audit and certify reserves for many major operators, following established reporting standards and providing credible, regulator- and investor-ready numbers. Their long history and specialized expertise in reserve estimation give them a reputation for thoroughness and independence that others in the field don’t primarily offer. By contrast, BP is an operator, Schlumberger is a service and technology provider, and Wood Mackenzie is a data and analysis firm—none are primarily known for conducting independent reserve audits at the scale and credibility that DeGolyer and MacNaughton maintain.