You have an App Engine application that needs to be updated. You want to test the update with production traffic before

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You have an App Engine application that needs to be updated. You want to test the update with production traffic before replacing the current application version.
What should you do?

A. Deploy the update using the Instance Group Updater to create a partial rollout, which allows for canary testing.
B. Deploy the update as a new version in the App Engine application, and split traffic between the new and current versions.
C. Deploy the update in a new VPC, and use Google's global HTTP load balancing to split traffic between the update and current applications.
D. Deploy the update as a new App Engine application, and use Google's global HTTP load balancing to split traffic between the new and current applications.