The correct answer are: Inspecting the reports of professional valuers who have been employed to value the company's assets and reviewing them for reasonableness; Performing analytical procedures on additions to non-current assets, disposals, and the depreciation charge; Reperforming a sample of depreciation calculations and calculations of the profit or loss on the disposal of assets.

Inspecting the reports of professional valuers, performing analytical procedures on non-current assets and checking a sample of depreciation calculations and calculations of the profit or loss on the disposal of assets all help to ensure that assets are correctly valued in the financial statements.

Taking a sample of invoices and checking to ensure that the related asset is on the company's premises ensures that the asset exists, but not that it is properly valued.

Checking to ensure that there is adequate physical security over the company's non-current assets is like a test of controls.