A shop's digital system shows an item as available although the physical stock is empty. What is the root cause?

Correct answer: Failure to update the digital record on time

The governing concept is data accuracy and freshness. A stock system is reliable only when sales, returns, and new deliveries are recorded promptly and correctly. If the physical item is gone but the digital record still says available, the record was not updated or synchronised in time. Therefore, option B identifies the root cause. QR-code size, a customer’s name, and screen appearance do not explain the mismatch.