The correct answer is B. The node with the highest priority will become a primary node. In an SRX chassis cluster, redundancy groups determine which node is primary and which node is secondary. Juniper states that when priorities are assigned to nodes in a redundancy group, the node with the higher configured priority is initially designated as the primary, while the other node becomes secondary. This is the direct mechanism an administrator uses to influence primary-node selection for a redundancy group.

Option A is wrong because the burnt-in address is not the administrative method used to designate the primary node. BIA can be part of deterministic hardware identity behavior, but primary election is controlled through redundancy-group priority, preemption behavior, and failover state. Option C is the opposite of Juniper behavior; the lower-priority node does not win the election. Option D is also wrong because a priority of one is still a valid low priority. The ineligible value is 0, and Juniper specifically warns about failover behavior involving nodes with priority 0 because such nodes are not ready to accept traffic.

Reference topics: HA Clustering, redundancy groups, node priority, primary/secondary election, preemption, chassis cluster failover.