Answer: Prior period adjustment resulting from the correction of an error.
Step-by-step explanation:
The Cash basis method is not acceptable under both IFRS and U.S. GAAP accounting principles and these are the principles followed by the majority of the world so Lore Co. was using the cash basis in violation of both conventions which means that their accounting records before the change are considered wrong and full of errors.
In changing to the acceptable principles, they are correcting that error and need to adjust prior periods for that error as well.