A customer has three LDAP servers: A master (ds1.example.com), another master (ds2.example com) and a read-only replica (ds3.example.com) used for the
IBM Security Access Manager (ISAM) V9.0. The deployment professional has configured the ISAM runtime using ds1.example.com as the registration server.
Which configuration will provide load balancing for LDAP read across all three servers and failover to ds2.example.com for LDAP write?
The configuration that provides load balancing for LDAP reads across all three servers and failover to ds2.example.com for LDAP writes must balance read requests evenly among the servers and specify a higher priority for write requests to the secondary master. In option C, all three servers are set for readonly access with equal priorities for read operations (priority 4), and ds2.example.com is set as readwrite with a slightly higher priority (priority 6). This configuration ensures that read operations are evenly distributed across all servers and that write operations will failover to ds2.example.com.
https://www.ibm.com/support/knowledgecenter/SSPREK_9.0.2/com.ibm.isam.doc/base_admin/concept/con_prefvalreplicaldapser.html it's not d, it's b