A developer created a landing page in CloudPages which return unique content when subscriber data is located on a related data extension. The developer does not know if all subscribers have rows in the related data extension, and want default content to render if no subscriber data is found on the related data extension.
Which best practice should the developer follow to control the unique and default content?

A developer is creating a custom preference center and wants to log unsubscribeevents from the CloudPage.
Which set of parameters should be captured and provided to the LongUnsubEvent Execute Call to ensure accurate unsubscribe information?

A developer identified duplicate contacts and wants to delete roughly 10 million subscribers using Contact Delete. How could the process be expedited?

Certification Aid wants to create Contacts in Marketing Cloud via API calls. Which API should be used for this? Choose 2.

A developer wants to build an email that dynamically populates the physical address of a company's locations using the variable address. The deployment goes to millions of subscribers and the developer wants the fastestpossible performance.
Which AMPscript solution should be recommended?