Option 1 -> Inventory investment refers to changes in stock of goods, not purchase of capital goods.
Option 2 -> Fixed investment specifically refers to expenditure on capital goods like machinery, equipment, and buildings.
Option 3 -> Gross investment includes both fixed investment and inventory investment, making it broader.
Option 4 -> Gross Domestic capital formation is the total addition to capital stock, including all types of investments.
Hence, Fixed investment -> Fixed investment specifically represents expenditure on the purchase of capital goods such as machinery, equipment, buildings, and other fixed assets that are used in production over multiple periods. These are tangible assets that form the fixed capital of an enterprise and are not meant for resale. Unlike inventory investment (changes in stock) or gross investment (which includes inventories), fixed investment directly captures spending on durable capital goods that enhance productive capacity. -> correct