Which security measure is used to protect physical documents from unauthorized access?

The correct choice involves the use of cross-cut shredders to protect physical documents from unauthorized access. These shredders are designed to cut paper into small, confetti-like pieces, making it exceedingly difficult for anyone to reconstruct the original document. By ensuring that sensitive information is destroyed in this manner, organizations can mitigate the risk of identity theft, corporate espionage, and other forms of fraud that could arise from improper handling of physical records.

Other options do not directly address the protection of physical documents. Data encryption is primarily used for safeguarding digital information by converting it into a coded format that is unreadable without a decryption key. Virtual private networks (VPNs) offer secure communication over the internet but are relevant to digital data transmission, not physical document security. Antivirus software is designed to detect and eliminate malware from computer systems, focusing on digital threats rather than physical document security. Hence, the use of cross-cut shredders stands out as the most effective measure for protecting physical documents from unauthorized access.