正解:C
Cisco Trustsec is a security architecture that enables scalable and dynamic access controls. It classifies traffic based on the contextual identity of the endpoint, such as the user, device type, location, and time of access, rather than relying solely on the IP address. This allows for more granular and flexible access controls that can adapt to the dynamic nature of networking environments and data centers. By using Security Group Tags (SGTs), Trustsec enforces access policies, making it easier to manage and secure network access in a more intuitive and policy-driven manner.