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.Based on these results， create an upgrade plan for the WAN lines.