Buildings are categorized as b) fixed asset.
Fixed assets are long-term tangible assets that a company uses in its operations to generate income. Unlike current assets, which are expected to be converted into cash within a year, fixed assets like buildings provide value over several years. They are not intended for sale in the regular course of business, and their depreciation is typically accounted for over their useful life. This classification reflects the building’s role in supporting the operating activities of a business.