Necessary to close web request stream?

Which way is preferrable?

A:

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
Stream reqStream = req.GetRequestStream();
reqStream.Write(data, 0, data.Length);
reqStream.Close();

B:

HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
req.GetRequestStream().Write(data, 0, data.Length);