You are creating an application using Visual Studio 2010. The application consumes a Windows Communication Foundation (WCF) service.You are adding a service reference to the WCF service. You need to ensure that the generated proxy does not block the calling thread when executing a service method.
What should you do when adding the service reference? （）

You are developing a Windows Communication Foundation (WCF) REST service to provide access to a library book catalog. The following code segment defines the service contract. (Line numbers are included for reference only.)
01 [ServiceContract()]
02 [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
03 public Class LibraryService
04 {
05 public Book GetBookByTitle(string title)
06 {
07 ...
08 }
09
10 [WebGet(UriTemplate = "Book/{id}")]
11 public Book GetBookById(string id)
12 {
13 ...
14 }
15 }Library patrons want the ability to search the catalog by title.You need to ensure that the GetBookByTitle method is exposed as a service method.Which code segment should you insert at line 04?（）