Which of the Following Are Changes in Accounting Principle

Which of the following are changes in accounting principle?
I. A change from LIFO to FIFO.
II. A change in estimated salvage value of depreciable asset.
III. A change from an accelerated depreciation method to straight line depreciation.
IV. Recording depreciation for the first time on machinery purchased five years ago.

A) I, II, III and IV
B) I, II and III
C) I, III and IV
D) I and III