По смыслу варианты 2 и 3 оба верные.
Я рекомендую выбрать вариант 2: descending method.
- The depleting method
- The descending method
- The declining method
- The discarding method
Depletion
Depletion is an accounting and tax concept used most often in mining, timber, petroleum, or other similar industries. The depletion deduction allows an owner or operator to account for the reduction of a product's reserves.
Descending depreciation = Accelerated depreciation
Accelerated depreciation refers to any one of several methods by which a company, for 'financial accounting' or tax purposes, depreciates a fixed asset in such a way that the amount of depreciation taken each year is higher during the earlier years of an asset’s life.
Declining depreciation
A declining balance method is a common depreciation-calculation system that involves applying the depreciation rate against the non-depreciated balance. Instead of spreading the cost of the asset evenly over its life, this system expenses the asset at a constant rate, which results in declining depreciation charges each successive period. For example, if an asset that costs $1,000 is depreciated at 25% each year, the deduction is $250 in the first year, $187 in the second year, and so on.
Discarding depreciation
Такого вообще нет!