According to the FortiOS 7.6 AWS Administration Guide and the Fortinet 7.4 Public Cloud Security study materials regarding infrastructure as code (IaC) for cloud deployments:

JSON Format Limitations (Option B): The exhibit shows an AWS CloudFormation template in JSON (JavaScript Object Notation) format. JSON, by its official specification, does not support comments. There is no native syntax (like // or /* */) to include remarks that are ignored by the CloudFormation parser.

YAML Support: To add descriptive comments---such as instructing other regional administrators to update the AMI ID---the administrator must convert the template into YAML format. YAML is a superset of JSON and specifically supports comments using the # character.

Best Practice for Multinational Deployments: For organizations operating across multiple AWS regions, using YAML is the recommended standard because it allows for inline documentation, making templates more maintainable and easier for different teams to understand regional requirements.

Why other options are incorrect:

Option A: Comments are part of the template file itself, not a parameter or flag within the aws cloudformation update-stack CLI command.

Option C: While # is the correct character for comments in YAML, it is invalid syntax in JSON and would cause the CloudFormation stack creation to fail with a parsing error.

Option D: The AWSTemplateFormatVersion '2010-09-09' is currently the only valid version for CloudFormation templates; updating it does not add JSON comment support.