According to the Salesforce documentation, an automation rule is an automation tool that can be used to send an email to a prospect when a form is submitted and a specific field value is selected on that form. An automation rule can be configured to trigger an action (such as sending an email) when a prospect meets certain criteria (such as submitting a form and having a specific field value). The criteria can be set to Match All or Match Any, depending on the logic required. In this case, the Match All option should be used, as the prospect needs to meet both conditions (form submission and field value) to receive the email. A completion action is another automation tool that can be used to perform an action after a prospect successfully completes a form, but it cannot be used to check for a specific field value. A dynamic list is a list of prospects that is updated automatically based on certain criteria, but it cannot be used to send an email directly. A list email is an email that is sent to a specific list of prospects, but it cannot be triggered by a form submission or a field value. Reference: Salesforce documentation