Final answer:
The incorrect statement about L2TP is that it must be used on HTML5-compliant devices. L2TP is a VPN protocol and is often paired with IPSec to provide secure data transmission, although L2TP alone does not provide encryption.
Step-by-step explanation:
The statement about L2TP that is NOT correct is a. It must be used on HTML5-compliant devices. Layer 2 Tunneling Protocol (L2TP) is indeed a popular VPN protocol used in various networks. Unlike implementation-specific protocols, L2TP does not require devices to be compliant with HTML5, as it operates at the network layer. L2TP is often paired with IPSec (Internet Protocol Security) to provide encryption, confidentiality, integrity, and authentication. Therefore, although L2TP by itself does not provide encryption, when it is paired with IPSec, this combination ensures secure data transmission across networks.