The correct answer is D, AWS Enterprise Support. This plan is designed for large-scale AWS customers and includes a designated Technical Account Manager (TAM) who proactively monitors the customer's environment, assists with optimization, and coordinates access to programs and AWS experts. The TAM helps to ensure that the customer's needs are met and that they are leveraging AWS services effectively. The other support plans, such as Basic, Developer, and Business, do not include a TAM as part of their offerings.