Which best practice should the developer use to ensure a blank email will not be sent?

A developer wants to create a complex dynamic email with three different sections and four different possible content blocks In each section. The email will be sent to an audience of over one million contacts.

Which best practice should the developer use to ensure a blank email will not be sent?
A . Send a test of every possible version using Test Send
B. Review every possible version using Subscriber Preview
C. Create separate emails for each version
D. Confirm every version has default content

Answer: D