I am in asp.net web api. In an API method, I am calling an external web service, that returns XML response. I don't want to deserialize it. I would rather like to send it to the client as is. Initially, I am storing the response in `XDocument` object but when my client specifies `application/xml` as accept header, I see the following exception

```
Type 'System.Xml.Linq.XDeclaration' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. If the type is a collection, consider marking it with the CollectionDataContractAttribute. See the Microsoft .NET Framework documentation for other supported types.

```

How do I get around this problem