title: Orderby statement uses First() method call, why is it needed?
body: <p>I'm new to Linq and I'm wondering why the <strong>First()</strong> method call is needed when ordering by the County in the following query.  Also, after knowing <em>why</em> it is needed, could the same result be accomplished by using the <strong>Last()</strong> method?</p>
  
  <pre><code>var hsQ = from hspt in hospitals
            orderby hspt.City
            group hspt by hspt.County into hsptGroup
            orderby hsptGroup.First().County
            select hsptGroup;
  </code></pre>
  
  <p>Note:  The above example is part of a Question/Answer from a book I'm reading, and the type <em>hospitals</em> is not defined explicitly for me to see.</p>