Which IS-IS design is required?

An engineer is creating a design to enable IPv6 to run on an existing IPv4 IS-IS network. The IPv4 and IPv6 topologies will match exactly, and the engineer plans to use the same router levels for each protocol per interface .

Which IS-IS design is required?
A . single topology without enabling transition feature
B . single topology with transition feature enabled
C . multi topology with transition feature enabled
D . multi topology without enabling transition feature

Answer: C

Explanation:

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_isis/configuration/15-mt/irs-15-mt-book/ip6-route-multi-isis.html