Accessing an IPv6 network via an IPv4 network is called what?

A.
CIDR

B.
NAT

C.
Translation

D.
Tunneling

Explanation:
Answer D is correct; accessing an IPv6 network via an IPv4 network is called tunneling.

Incorrect Answers and Explanations: A, B, and C: Answers A, B, and C are incorrect. CIDR is Classless Inter-domain Routing, a way to create flexible subnets. NAT is Network Address Translation, which translates one IP address for another. Translation is a distracter answer.