How would you mark up a header for a table row?
<table> <tr> <thead scope="row"> Header </thead> <td>10</td> <td>18</td> </tr> </table>
<table> <tr> <th scope="row">Header</th> <td>10</td> <td>18</td> </tr> </table>
<table> <thead scope="row"> <th row="1">Header</th> </thead> <tr> <td>10</td> <td>18</td> </tr> </table>
<table> <tr> <th>Header</th> <td>10</td> <td>18</td> </tr> </table>