设置作为主接口的逻辑通道呼叫8次仍未成功为切换到备份接口，每隔60秒检查一次主逻辑通道是否恢复Up，这样的配置应为（）

A、backup state-down8 state-up60

B、backup state-down60；backup state-up8

C、backup state-down8；backup state-up60

D、backup state-down8；backup state-uptime60