Final answer:
Authentication measures are necessary to ensure authorized access to health care information.
Step-by-step explanation:
The safeguard that is necessary to ensure only authorized individuals have access to health care information is authentication measures. Authentication measures verify the identity of users before granting them access to sensitive information. This could include using methods such as usernames and passwords, biometric authentication, or two-factor authentication.
Firewalls help protect against unauthorized access to a computer network and can be part of the overall security measures of an organization, but they are not specifically designed for user authentication.
Encryption is the process of encoding information to prevent unauthorized access, but it does not verify the identity of users.
Anti-virus software is used to detect and remove malware from computers, but it does not specifically address user authentication.