Officer may verify:

For effective verification and audit, an officer needs a holistic view. Option C is correct because it allows for cross-referencing physical stock with corresponding financial records and documents. This ensures that what is physically present matches what is recorded in the books, preventing discrepancies and fraud.

• Option A, 'Only physical stock', is insufficient as it doesn't confirm ownership or transaction history.
• Option B, 'Only sale records', provides only one side of the inventory movement and doesn't account for purchases or current stock.
• Option D, 'Only invoices', while important, represents only a part of the documentation and doesn't cover physical verification or other financial records.