An application will upload data by using HTML form-based encoding. The application uses a method named
SendMessage. The SendMessage() method includes the following code. (Line numbers are included for
reference only.)
01 public Task<byte[]> SendMessage(string url, int intA, int intB)
02 {
03 var client = new WebClient();
04
05 }
The receiving URL accepts parameters as form-encoded values. You need to send the values intA and intB
as form-encoded values named a and b, respectively. Which code segment should you insert at line 04?

A.
var data = string.Format(“a={0}&b={1}”, intA, intB);
return client.UploadStringTaskAsync(new Uri(url), data);

B.
var data = string.Format(“a={0}&b={1}”, intA, intB);
return client.UploadFileTaskAsync(new Uri(url), data);

C.
var data = string.Format(“a={0}&b={1}”, intA, intB);
return client.UploadDataTaskAsync(new Uri(url), Encoding.UTF8.GetBytes(data));

D.
var nvc = new NameValueCollection() { { “a”, intA.ToString() }, { “b”,
intB.ToString() } };
return client.UploadValuesTaskAsync(new Uri(url), nvc);

Explanation:
WebClient.UploadValuesTaskAsync – Uploads the specified name/value collection to the resource
identified by the specified URI as an asynchronous operation using a task object. These methods do not block
the calling thread. http://msdn.microsoft.com/en-us/library/system.net.webclient.uploadvaluestaskasync.aspx