A. [SecurityPermission(SecurityAction.Demand,Flags=SecurityPermissionFlag.UnmanagedCode)]
B. [SecurityPermission(SecurityAction.LinkDemand,Flags=SecurityPermissionFlag.UnmanagedCode)]
C. [SecurityPermission(SecurityAction.Assert,Flags = SecurityPermissionFlag.UnmanagedCode)]
D. [SecurityPermission(SecurityAction.Deny,Flags = SecurityPermissionFlag.UnmanagedCode)]