Explanation

In the AWS Shared Responsibility Model:

AWS is responsible for:

• Security OF the cloud
• Infrastructure security (hardware, software, facilities)
• Host operating systems and virtualization
• Configuration of infrastructure devices
• Software that powers Availability Zones

Customer is responsible for:

• Security IN the cloud
• Management of guest operating systems
• Application security
• Customer data
• Identity and access management
• Network traffic protection
• Server-side encryption

Therefore, management of the guest operating systems is clearly the customer's responsibility, while AWS handles the underlying infrastructure, host systems, and Availability Zone management.