Staging the upgrade by first updating a non-primary node, followed by the primary node, and then the remaining nodes For a multi-node Tableau Server upgrade, it is crucial to stage the upgrade process to minimize disruption. This involves first upgrading a non-primary node, allowing for testing and validation before proceeding with the primary node and then the remaining nodes. This staged approach helps ensure stability and availability of the server throughout the up-grade process. Option A is incorrect because upgrading all nodes simultaneously could lead to significant downtime if issues arise. Option B is incorrect as performing the upgrade during business hours can disrupt users and business operations. Option D is incorrect because upgrading the primary node first can pose a risk if new or untested changes impact server stability.