A customer asked a consultant to create the infrastructure for an application.  The application is designed to charge customers for conferencing services based on usage.  To determine if a Storage Area Network （SAN） is the best storage solution， which of the following questions is most appropriate？（）

• A、Will the application require a database？
• B、Which operating system does the application require？
• C、Will the data need to be backed up in real time？
• D、Does the application share data among the servers？