Rule: Capital assets include property (real and personal) held by the taxpayer for investment, such as:

• Personal automobile of the taxpayer

• Furniture and fixtures in the home of the taxpayer

• Stocks and securities of all types (except those held by dealers)

• Personal property of a taxpayer not used in a trade or business

• Real property not used in a trade or business

• Interest in a partnership

• Goodwill of a corporation

• Copyrights, literary, musical, or artistic compositions purchased

• Other assets held for investment

Items that are NOT capital assets include:

• Property normally included in inventory or held for sale to customers in the ordinary course of business

• Depreciable personal property and real estate used in a trade or business

• Accounts and notes receivable arising from sales or services in the taxpayer's business

• Copyrights, literary, musical, or artistic compositions held by the original artist (with the exception of musical compositions held by the original artist)

• Treasury stock (not an ordinary asset and not subject to capital gains treatment)

Choice "D" is correct. Per the above information and rule, real property not used in a trade or business (e.g., land held for investment) is a capital asset.
Choice "c" is incorrect. Per the above information, property normally included in inventory or held for sale to customers in the ordinary course of business is NOT a capital asset.
Choice "a" is incorrect. Per the above information, accounts and notes receivable arising from sales or services in the taxpayer's business are NOT capital assets.
Choice "b" is incorrect. Per the above information, depreciable personal property and real estate used in a trade or business (such as a computer system) is NOT a capital asset.