If You Want CloudFormation Stack Status Updates to Show Up

Multiple Choice

If you want CloudFormation stack status updates to show up in a continuous delivery system in as close to real time as possible, how should you achieve this?

A) Use a long-poll on the Resources object in your CloudFormation stack and display those state changes in the UI for the system.
B) Use a long-poll on the <code>ListStacksAPI</code> call for your CloudFormation stack and display those state changes in the UI for the system.
C) Subscribe your continuous delivery system to an SNS topic that you also tell your CloudFormation stack to publish events into.
D) Subscribe your continuous delivery system to an SQS queue that you also tell your CloudFormation stack to publish events into.