Exam NCP-MCI-7.5 Topic 1 Question 36 Discussion

Nutanix DR documentation for test failover states that recovered test VMs are brought up in a test virtual network at the recovery AZ, separate from production. Nutanix also documents that when multiple recovery directions or multiple recovery AZs are involved, recovery planning should be created per target direction and the required production and test network mappings need to exist for the recovery plan being tested. If recovery must be tested in both directions between the two clusters, each side effectively needs a production network and a test network. That makes two production networks and two test networks the most complete and correct answer.
This question is really about symmetry. One-direction failover testing can be done with a simpler mapping set, but the moment the requirement says test recovery in both directions, each cluster must be able to act as a recovery site and provide an isolated test-recovery network. That is why a single shared test network is not the best answer here. Nutanix's recovery-plan structure and test-failover guidance support this interpretation.
Therefore C is the correct and most practical answer.