When converting between True and Magnetic bearings and you have no verified variation, what should you do?

When converting between True and Magnetic bearings and you have no verified variation, what should you do?

• A. Use the last known variation and ignore updates.
• B. Determine or assume the latest published variation; otherwise, do not navigate solely on an unconfirmed bearing.
• C. Convert using local time as a substitute.
• D. Rely on gyro compass bearing only.

Answer: (B)