You have an Exchange Server 2010 organization.You need to prevent users from changing their password by using Outlook Web App （OWA）.What should you do？（）

• A、Create a Group Policy Object.
• B、Create an Outlook Web App Mailbox policy.
• C、Modify the authentication settings of the OWA virtual directory.
• D、Modify the authentication settings of the IISADMPWD virtual directory.