Answer: Create a custom image from the existing disk. Create an instance template from the custom image. Create an autoscaled managed instance group from the instance template.

The correct answer is C because it follows the proper Google Cloud workflow for creating an autoscaled managed instance group (MIG) from an existing instance. A custom image created directly from the existing disk captures the application state without requiring the instance to be stopped, which is suitable for a stateless application. The instance template is then created from this custom image, which is the standard approach as instance templates require an image source (custom or public). Finally, the autoscaled MIG is created from the instance template, enabling automatic scaling during peak hours to address performance issues. Option A is incorrect because instance templates cannot be created directly from snapshots; snapshots must first be converted to custom images. Option B is incorrect because MIGs cannot be created directly from custom images; an instance template is required as an intermediate step. Option D is incorrect because instance templates cannot be created directly from existing disks, and custom images cannot be created from instance templates. The community discussion strongly supports C, with high upvotes and reasoning that aligns with Google Cloud best practices.

Author: LeetQuiz Editorial Team