MACsec can provide secure services during MAC-layer data transmitting and receiving.

Comprehensive and Detailed In-Depth Explanation:

MACsec (Media Access Control Security)is a security protocol that provides securecommunication over Ethernet links. It operates at the MAC layer (Layer 2) and offers the following key security services:

Integrity Check (B):Ensures that data has not been tampered with during transmission.

User Data Encryption (C):Protects data confidentiality by encrypting the payload.

Data Source Authenticity Verification (D):Confirms that the data originates from a legitimate source by using security associations.

Controllability Check (A)is not a service provided by MACsec. The term "controllability" typically relates to network management and configuration control rather than data security. MACsec primarily focuses on protecting data integrity, confidentiality, and authenticity, rather than controlling network elements or configurations.