A company has a multi-account structure in AWS Organizations. They want to share a central AWS Transit Gateway with all accounts in a specific Organizational Unit (OU). What is the MOST efficient way to achieve this?

Create VPC peering connections between the central account and all member accounts.

Use AWS Resource Access Manager (RAM) to share the Transit Gateway with the OU ARN.

Share the Transit Gateway by adding each account ID manually in the TGW resource policy.

Use AWS Service Catalog to provision Transit Gateways in each account.