A company uses an organization in AWS Organizations to manage AWS accounts that contain applications.

CloudWatch cross-account observability is a feature that allows you to monitor and troubleshoot applications that span multiple accounts within a Region. You canseamlessly search, visualize, and analyze your metrics, logs, traces, and Application Insights applications in any of the linked accounts without account boundaries1. To enable CloudWatch cross-account observability, you need to set up one or more AWS accounts as monitoring accounts and link them with multiple source accounts. A monitoring account is a central AWS account that can view and interact with observability data shared by other accounts. A source account is an individual AWS account that shares observability data and resources with one or more monitoring accounts1. To create links between monitoring accounts and source accounts, you can use the CloudWatch console, the AWS CLI, or the AWS API. You can also use AWS Organizations to link accounts in an organization or organizational unit to the monitoring account1. CloudWatch provides a CloudFormation template that you can deploy in each source account to share observability data with the monitoring account. The template creates a sink resource in the monitoring account and an observability link resource in the source account. The template also creates the necessary IAM roles and policies to allow cross-account access to the observability data2. Therefore, the solution that meets the requirements of the question is to enable CloudWatch cross-account observability for the monitoring account and deploy the CloudFormation template provided by the monitoring account in each AWS account to share the data with the monitoring account.

The other options are not valid because:

Service control policies (SCPs) are a type of organization policy that you can use to manage permissions in your organization. SCPs offer central control over the maximum available permissions for all accounts in your organization, allowing youto ensure your accounts stay within your organization’s access control guidelines3. SCPs do not provide access to CloudWatch in the monitoring account, but rather restrict the actions that users and roles can perform in the source accounts. SCPs are not required toenable CloudWatch cross-account observability, as the CloudFormation template creates the necessary IAM roles and policies for cross-account access2.

IAM users are entities that you create in AWS to represent the people or applications that use them to interact with AWS. IAM users can have permissions to access the resources in your AWS account4. Configuring a new IAM user in the monitoring account and an IAM policy in each AWS account to have access to query and visualize the CloudWatch data in the account is not a valid solution, as it does not enable CloudWatch cross-account observability. This solution would require the IAM user to switch between different accounts to view the observability data, which is not seamless and efficient. Moreover, this solution would not allow the IAM user to search, visualize, and analyze metrics, logs, traces, and Application Insights applications across multiple accounts in a single place1.

Cross-account IAM policies are policies that allow you to delegate access to resources that are in different AWS accounts that you own. You attach a cross-account policy to a user or group in one account, and then specify which accounts theuser or group can access5. Creating a new IAM user in the monitoring account and cross-account IAM policies in each AWS account is not avalid solution, as it does not enable CloudWatch cross-account observability. This solution would also require the IAM user to switch between different accounts to view the observability data, which is not seamless and efficient. Moreover, this solution would not allow the IAM user to search, visualize, and analyze metrics, logs, traces, and Application Insights applications across multiple accounts in a single place1.