A managed instance group serving live traffic must be updated to a new version without reducing available capacity during deployment. What should you do?

The correct option ensures a zero-downtime update by using a rolling update with specific parameters. Setting maxSurge to 1 means that the managed instance group (MIG) will create one new instance with the updated configuration before terminating an old one. This maintains or temporarily increases capacity. Setting maxUnavailable to 0 ensures that no instances are taken offline until a new, healthy instance is available, thus preventing any reduction in available capacity. The other options are incorrect because: maxSurge set to 0 and maxUnavailable set to 1 would cause a temporary reduction in capacity as an instance would be taken down before a new one is brought up. Creating a new MIG and then deleting the old one is a blue/green deployment strategy, which is more complex than a rolling update for this scenario and can lead to higher resource consumption during the transition. Updating the instance template and then manually deleting instances would cause downtime as instances are removed and then recreated, violating the requirement to not reduce available capacity.