[单项选择] You have two servers named FC1 and FC2 that run Windows Server 2008 Enterprise Edition. Both servers have the Failover Clustering feature installed. You configure the servers as a two-node cluster. The cluster runs an application named APP1. Business hours for your company are 09：00 to 17：00. APP1 must be available during these hours. You configure FC1 as the preferred owner for APP1. You need to prevent failback of the cluster during business hours. What should you do？（）
A. Set the Period option to 8 hours in the Failover properties.
B. Set the Allow failback option to allow failback between 17 and 9 hours in the Failover properties.
C. Enable the Prevent failback option in the Failover properties.
D. Enable the If resource fails， attempt restart on current node policy for all APP1 resources. Set the maximum restarts for specified period to 0.