Which action do you take to resolve the issue?

Refer to the exhibit.

You are implementing DMVPN Phase 3 in an existing network that uses DMVPN Phase1. You configure NHRP, but the creation of the spoke-to-spoke tunnel fails.

Which action do you take to resolve the issue?
A . Remove the multicast flag from the NHRP configuration.
B . Configure the tunnel of the hub by using point-to-point tunnel mode.
C . Configure the tunnel of the spoke by using mGRE tunnel mode.
D . Remove NHRP redirects from the hub configuration.

Answer: C

Explanation:

Reference: http://www.patrickdenis.biz/blog/dmvpn-phase-1-2-and-3/