Final answer:
In a Smart Campaign, an email must be approved to be used, which makes option B the correct answer. Emails can include tokens and do not have to be Local Assets, as the approval process is pivotal to campaign readiness.
Step-by-step explanation:
In order for an email to be used in a Smart Campaign, it must be approved. Option B is the correct answer. When creating a Smart Campaign, especially in marketing automation platforms like Marketo, emails and other assets involved in the campaign must go through an approval process. This ensures that all the content is final, correctly formatted, and ready to be sent out. An email does not necessarily need to include a token (Option A) or be a Local Asset (Option D), and it certainly can have tokens (contrary to Option C); tokens are used for dynamic content but are not a requirement for email approval in a Smart Campaign.