A.[FileIOPermission(SecurityAction.RequestOptional,AllLocalFiles = FileIOPermissionAccess.Read)]
B.[FileIOPermission(SecurityAction.RequestMinimum, AllFiles = FileIOPermissionAccess.Read)]
C.[FileIOPermission(SecurityAction.RequestRefuse, AllFiles = FileIOPermissionAccess.Read)]
D.[FileIOPermission(SecurityAction.RequestOptional, AllFiles = FileIOPermissionAccess.Read)]