Which criteria must be met for a subscription list to be visible in the toolbox?

For a subscription list to be visible in the toolbox within the Dynamics 365 Marketing application, it needs to meet specific criteria that ensure the list is both accessible and relevant for marketing activities. The key requirement is that the marketing list must be active and the subscription field must be set to True.

An active marketing list indicates that the list is currently available for campaigns and communications. By having the subscription field set to True, it signifies that recipients on this list have opted in to receive communications, aligning with compliance regulations and best practices for marketing outreach.

In contrast, other options do not fulfill one or both of these essential criteria:

• Published marketing lists that are set to False would imply that they are not intended for active subscription communications, making them unsuitable for visibility in the context of subscriptions.
• Active marketing lists with the subscription field set to False would suggest that recipients have not consented to receive communications, which directly conflicts with the purpose of a subscription list.

Thus, option D correctly encapsulates the criteria necessary for a subscription list to be visible, reinforcing the importance of both the status of the list and the consent of the subscribers.