Which method should be used?

A customer has several values that need to be used in the body of an email send:

* The data would be stored in a reference data extension, related on SubscriberKey.

* There may be one or more records for each subscriber.

* The audience is generally over 1 million subscribers.

* The content is time sensitive and should be sent as quickly as possible.

* The customer is not using "catch and release" sending.

* The reference data extension contains 25 columns.

Which method should be used?
A . AMPscript a single Lookup Function
B . Server Side Javascript a single LookupOrderedRows Function
C . AMPscript a single LookupOrderedRows Function
D . Dynamic content via the Dynamic Content Wizard