For the restaurant supply company's need to update their trade show contact collection method:

B. Microsite with Smart Capture to store entrants on a data extension: Smart Capture forms on a microsite provide a direct, digital method to collect entries efficiently and store them directly into a data extension.

D. Data Extension with double opt-in status defined: This setup helps manage consent and ensures compliance with email marketing regulations, as it allows entrants to confirm their subscription to the newsletter through a follow-up email.

These components provide an updated and efficient method for capturing and managing trade show contacts, while also ensuring compliance with marketing regulations.