Explanation: According to the [Salesforce documentation], the recommended Marketing Cloud Account Engagement asset to use for progressive profiling is a Marketing Cloud Account Engagement form. A Marketing Cloud Account Engagement form is a web form that can be used to collect information from prospects and store it in Marketing Cloud Account Engagement. A Marketing Cloud Account Engagement form can be configured to use progressive profiling, which is a feature that allows the form to display different fields based on the information that is already known about the prospect. This way, the form can collect more information over time, without asking the same questions repeatedly or overwhelming the prospect with too many fields at once. A Marketing Cloud Account Engagement landing page without a form, a Marketing Cloud Account Engagement form handler, or a third party form are not recommended for progressive profiling, as they do not have the same functionality and flexibility as a Marketing Cloud Account Engagement form.