Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
Zweikanalton
Table title:
How It Works
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > mode </th><th colspan=1 rowspan=1 > existing OIRT 6.5 MHz or BG 5.5 MHz sound carrier contains: </th><th colspan=1 rowspan=1 > 2nd OIRT 6.258 MHz or BG 5.742 MHz carrier contains: </th><th colspan=1 rowspan=1 > pilot tone in 2nd carrier: </th></tr>
<tr> <td colspan=1 rowspan=1 > mono </td><td colspan=1 rowspan=1 > mono </td><td colspan=1 rowspan=1 > carrier is absent </td><td colspan=1 rowspan=1 > none </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > stereo </td><td colspan=1 rowspan=1 > mix of left & right (L+R) </td><td colspan=1 rowspan=1 > right audio channel (R) </td><td class="highlighted"  colspan=1 rowspan=1 > 54.6875 kHz 50% AM with 117.5 Hz </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > bilingual </td><td colspan=1 rowspan=1 > 1st language </td><td colspan=1 rowspan=1 > 2nd language </td><td class="highlighted"  colspan=1 rowspan=1 > 54.6875 kHz 50% AM with 274.1 Hz </td></tr>
</table>
Question:
What does the second carrier contain?
Answer:
The second carrier contains a 54.6875 kHz pilot tone for stereo or bilingual.