Comprehensive and Detailed Explanation:
IPSec (Internet Protocol Security)is the best choice forsecure communication over the internet, as it providesencryption, authentication, and data integrity. It is widely used inVPNs and site-to-site secure tunnels.
Breakdown of Options:
* A. DCI (Data Center Interconnect)- A general term forlinking data centers, but it doesn't specify a secure tunneling protocol.
* B. GRE (Generic Routing Encapsulation)- Encapsulates traffic butlacks encryption, making itless secure than IPSec.
* C. VXLAN (Virtual Extensible LAN)- Used forLayer 2 network overlays,not for securing communication over the internet.
* D. IPSec-#Correct answer.Providesencryption, authentication, and integrityfor data over the internet.