You are a security architect working for a large antivirus company. The production environment has recently been moved to AWS and is in a public subnet. You are able to view the production environment over HTTP however when your customers try to update their virus definition files over a custom port, that port is blocked. You log in to the console and you allow traffic in over the custom port. How long will this take to take effect?

A. Straight away but to the new instances only.
B. Immediately.
C. After a few minutes this should take effect.
D. Straight away to the new instances, but old instances must be stopped and restarted before the new rules apply.

Answer: B. Immediately.