[单选题]46、 When preparing to deploy HA methods for failover puposes, which of the following require configuration to the AnyConnect client software?当出于故障切换的目的而准备配置HA的方法时，下面的哪一种方法需要在AnyConnect客户端软件中配置?
A. VPN load balancing VPN负载平衡
B. Active/standby failover active/standby故障切换
C. External load balancer 外部负载平衡器
D. AnyConnect redundant peering AnyConnect冗余对等体