Which of the following is a common method used to prevent unauthorized access to data?

Access controls are a fundamental security measure used to prevent unauthorized access to data. They work by restricting access to information based on the identity of the user and their assigned permissions. This method ensures that only authorized individuals can view, modify, or manage sensitive information, thereby protecting the integrity and confidentiality of that data.

Access control mechanisms include various methods such as authentication (ensuring users are who they claim to be), authorization (granting appropriate permissions based on user roles), and accounting (tracking user actions). By implementing strong access controls, organizations can significantly reduce the risk of data breaches and maintain security compliance with regulations.

In contrast, the other options do not effectively prevent unauthorized access to data. Data deletion can remove information but does not control access; data duplication may create multiple copies of data, potentially leading to more vulnerabilities; and data sharing involves distributing information, which could increase exposure to unauthorized users if not managed properly.