正解:A
TCAM (Ternary Content Addressable Memory) and the MAC address table serve different purposes in networking devices. The MAC address table, also known as the CAM (Content Addressable Memory) table, is used for making Layer 2 forwarding decisions. It stores MAC addresses and the corresponding port numbers to which they are attached. On the other hand, TCAM is a specialized type of CAM that is used for high-speed packet classification by storing ACL (Access Control Lists), QoS (Quality of Service) policies, and routing information. TCAM supports more complex lookups, such as longest prefix match, which are essential for Layer 3 routing decisions.
https://community.cisco.com/t5/networking-documents/cam-content-addressable-memory-vs-tcam-ternary-conte When using Ternary Content Addressable Memory (TCAM) inside routers it's used for faster address lookup that enables fast routing.
In switches Content Addressable Memory (CAM) is used for building and lookup of mac address table that enables L2 forwarding decisions.
Besides Longest-Prefix Matching, TCAM in today's routers and multilayer Switch devices are used to store ACL, QoS and other things from upper-layer processing.