What is the most likely cause of this error?

A user in the campaign manager group opens a workflow and clicks to open a delivery.

After the delivery opens, the following error is thrown:

Cannot load document of type ‘Deliveries (nms:delivery)’ satisfying condition ‘(@id=12345678) AND ((@deleteStatus = 0))’.

The requested database record does not exist.

What is the most likely cause of this error?
A . The user does NOT have access to the workflow folder.
B . The delivery has already been sent and therefore CANNOT be opened.
C . The MTA process is NOT running on the instance.
D . The user is NOT in the Delivery operators group and does NOT have permission.

Answer: B

Explanation:

Reference: https://experienceleaguecommunities.adobe.com/t5/adobe-campaign-standard/delivery-error/qaq-p/234713