Which of the Following Is an Example of an Error

Which of the following is an example of an error that should be corrected?

A) Switching from straight-line to the declining balance method of depreciation.
B) Changing from weighted average to the first-in, first out method of inventory valuation.
C) Using 5% for bad debts provision, but 1% is required in the company's procedures manual.
D) Starting to capitalize fixed assets under $1,000 which were previously considered immaterial.