You need to ensure that there is adequate bandwidth available to meet the service-level agreement requirements. Which action or actions should you perform?（）

• A、Upgrade all WAN lines in six months.  
• B、Upgrade all WAN lines prior to implementing NewApp. 
• C、Analyze the cause of a peak in network usage in February.
• D、Analyze network usage characteristics for NewApp.  
• E、Based on these results, create an upgrade plan for the WAN lines.