B is correct because AWS Enterprise Support is the AWS Support plan that provides concierge service, a designated AWS technical account manager (TAM), and technical support that is available 24 hours a day, 7 days a week. This plan is designed for customers who run mission-critical workloads on AWS and need the highest level of support. A is incorrect because AWS Basic Support is the AWS Support plan that provides customer service and support for billing and account issues, service limit increases, and technical support for a limited set of AWS services. It does not provide concierge service, a designated TAM, or 24/7 technical support. C is incorrect because AWS Business Support is the AWS Support plan that provides customer service and support for billing and account issues, service limit increases, and technical support for all AWS services, as well as access to AWS Trusted Advisor and AWS Support API. It does not provide concierge service or a designated TAM. D is incorrect because AWS Developer Support is the AWS Support plan that provides customer service and support for billing and account issues, service limit increases, and technicalsupport for all AWS services, as well as access to AWS Trusted Advisor. It does not provide concierge service, a designated TAM, or 24/7 technical support.