An IT department manages a portfolio with Windows and Linux (Amazon and Red Hat Enterprise Linux) servers both on-premises and on AWS. An audit reveals that there is no process for updating OS and core application patches, and that the servers have inconsistent patch levels. Which of the following provides the MOST reliable and consistent mechanism for updating and maintaining all servers at the recent OS and core application patch levels?

A. Install AWS Systems Manager agent on all on-premises and AWS servers. Create Systems Manager Resource Groups. Use Systems Manager Patch Manager with a preconfigured patch baseline to run scheduled patch updates during maintenance windows.
B. Install the AWS OpsWorks agent on all on-premises and AWS servers. Create an OpsWorks stack with separate layers for each operating system, and get a recipe from the Chef supermarket to run the patch commands for each layer during maintenance windows.
C. Use a shell script to install the latest OS patches on the Linux servers using yum and schedule it to run automatically using cron. Use Windows Update to automatically patch Windows servers.
D. Use AWS Systems Manager Parameter Store to securely store credentials for each Linux and Windows server. Create Systems Manager Resource Groups. Use the Systems Manager Run Command to remotely deploy patch updates using the credentials in Systems Manager Parameter Store