What is the primary reason for this?

High Availability Deployment

In order to be HA, you must install Tableau Server on at least 3 nodes .

What is the primary reason for this?
A . The primary reason for this is that Tableau Server relies on the concept of a quorum to determine if the cluster is in a consistent state to protect against network partitioning problems.
B . The primary reason is that 2 nodes are simply not enough from a compute power perspective to shoulder all the load in a HA deployment

Answer: A

Explanation:

Tableau Server High Availability Whitepaper https://www.tableau.com/learn/whitepapers/tableau-server-high-availability-delivering-mission-critical-analytics-scale