The correct answer is B because setting VM-Host affinity ensures that the DB Server VMs are not migrated to another host during the LCM upgrade process. This way, the DB Server VMs can continue to serve the database requests without interruption. Option A is incorrect because updating the Nutanix cluster does not prevent the DB Server VMs from being moved to another host. Option C is incorrect because removing the Nutanix cluster from NDB will make the DB Server VMs unmanaged by NDB and lose the benefits of NDB features. Option D is incorrect because unsetting VM-Host affinity will allow the DB Server VMs to be migrated to another host during the LCM upgrade process, which may cause downtime or performance degradation.
References: The following sources provide more information about the LCM upgrades and VM-Host affinity in NDB:
* Nutanix Database Management & Automation (NDMA) course, Module 6: Administering an NDB Environment, Lesson 6.3: Performing NDB Software Upgrades
* Nutanix Certified Professional - Database Automation (NCP-DB) v6.5, Knowledge Objectives, Section
6 - Administer an NDB Environment
* Nutanix Database Service (NDB) User Guide, Chapter 8: Administering an NDB Environment, Section
8.3: Performing NDB Software Upgrades
* Nutanix Support & Insights, Your guide to the Upgrades, LCM Design
* Nutanix Life Cycle Manager Guide, Chapter 3: Upgrading Software and Firmware, Section 3.2:
Preparing for an Upgrade, VM-Host Affinity