Explain how the choice of one of the following accounting methods over the other raises or lowers

Question:

Explain how the choice of one of the following accounting methods over the other raises or lowers a company’s net income during a period of continuing inflation.
(a) Use of FIFO instead of LIFO for inventory costing.
(b) Use of a 6-year life for machinery instead of a 9-year life.
(c) Use of straight-line depreciation instead of declining-balance depreciation.