The Support Manager wants to send an automatic email to the Case Contact when a case is closed. Which automation tool can the administrator use?

Validation rules enforce data integrity by preventing users from saving records that don't meet specified criteria, but they do not send emails.

Case Auto-Response Rules are used to send an automatic email acknowledgment to customers when a case is submitted, not when it is closed.

Sharing rules are used to extend record access to users based on criteria or ownership, but they do not perform automated actions like sending emails.

Workflow Rules are a declarative automation feature in Salesforce that can perform actions, such as sending email alerts, when predefined criteria are met on a record. An administrator can configure a Workflow Rule to trigger an email alert to the Case Contact when the Case Status field changes to 'Closed'.