An administrator at Universal Containers is reviewing current security settings in the company's Salesforce org. What should the administrator do to prevent unauthorized access to Salesforce?

Disabling TLS (Transport Layer Security) requirements would reduce security by allowing unencrypted communication, making data vulnerable to interception and thereby increasing the risk of unauthorized access.

Multi-factor authentication (MFA) significantly enhances security by requiring users to provide two or more verification factors to gain access, making it much harder for unauthorized individuals to log in even if they obtain a password.

Enabling caching and autocomplete on the login page makes it easier for users to log in, but it can also expose credentials on shared computers, thereby reducing security and increasing the risk of unauthorized access.

Customizing organization-wide defaults controls the default visibility of records *after* a user has logged in, but it does not prevent unauthorized users from gaining initial access to the Salesforce org itself.