Accounting standard 8 is concerned with:

Valuation of inventories
Accounting for fixed assets
Accounting for research and development
Depreciation accounting

The correct answer is: A. Valuation of inventories.

Accounting Standard 8 (AS 8) is an accounting standard issued by the Institute of Chartered Accountants of India (ICAI). It is applicable to all companies, including public companies, private companies, and unlisted companies. The standard deals with the valuation of inventories, which are assets held for sale in the ordinary course of business or for consumption in the production of goods or services for sale.

The standard requires that inventories be valued at the lower of cost and net realizable value. Cost is the amount of cash or cash equivalents paid or the fair value of other consideration given to acquire an asset at the time of its acquisition or construction. Net realizable value is the estimated selling price in the ordinary course of business less the estimated costs of completion and the estimated costs necessary to make the sale.

The standard also provides guidance on the measurement of cost, the determination of net realizable value, and the disclosure of information about inventories.

Option B, Accounting for fixed assets, is incorrect because AS 10 deals with accounting for fixed assets. Fixed assets are tangible assets that are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes and are expected to be used for more than one period.

Option C, Accounting for research and development, is incorrect because AS 26 deals with accounting for research and development. Research and development is the planned search or critical investigation aimed at discovery of new knowledge with the hope of developing new products or processes or improving existing products or processes.

Option D, Depreciation accounting, is incorrect because AS 16 deals with depreciation accounting. Depreciation is the systematic allocation of the depreciable amount of an asset over its useful life. The depreciable amount of an asset is its cost less its residual value. The useful life of an asset is the period over which it is expected to be used by the entity.