Which code segment should you insert at line 04?

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.)

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.
Option A

B.
Option B

C.
Option C

D.
Option D

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