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:
Sofia Carson
Table title:
Music videos
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > Title </th><th colspan=1 rowspan=1 > Other artist(s) </th><th colspan=1 rowspan=1 > Director(s) </th><th colspan=1 rowspan=1 > Ref. </th></tr>
<tr> <th colspan=5 rowspan=1 > As lead artist </th></tr>
<tr> <td colspan=1 rowspan=1 > 2015 </td><th colspan=1 rowspan=1 > "Rotten to the Core" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > Naren Wilks and Adam Santelli </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=5 > 2016 </td><th colspan=1 rowspan=2 > "Love Is the Name" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > Hannah Lux Davis </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=1 > J Balvin </td><td colspan=1 rowspan=1 > Hannah Lux Davis </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Wildside" </th><td colspan=1 rowspan=1 > Sabrina Carpenter </td><td colspan=1 rowspan=1 > Unknown </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Full Throttle" </th><td colspan=1 rowspan=1 > — </td><td colspan=1 rowspan=1 > Unknown </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Jolly to the Core" </th><td colspan=1 rowspan=1 > Dove Cameron, Cameron Boyce and Booboo Stewart </td><td colspan=1 rowspan=1 > Unknown </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td colspan=1 rowspan=3 > 2017 </td><th colspan=1 rowspan=1 > "Back to Beautiful" </th><td colspan=1 rowspan=1 > Alan Walker </td><td colspan=1 rowspan=1 > Emil Nava </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Ways to Be Wicked" </th><td colspan=1 rowspan=1 > Dove Cameron, Cameron Boyce and Booboo Stewart </td><td colspan=1 rowspan=1 > Kenny Ortega </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=1 rowspan=1 > "Ins and Outs" </th><td colspan=1 rowspan=1 > – </td><td colspan=1 rowspan=1 > John-Michael Triana </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=2 > 2018 </td><th class="highlighted"  colspan=1 rowspan=1 > "Rumors" </th><td class="highlighted"  colspan=1 rowspan=1 > R3HAB </td><td colspan=1 rowspan=1 > Mario Gonsalves </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th class="highlighted"  colspan=1 rowspan=1 > "Different World" (Vertical Video) </th><td class="highlighted"  colspan=1 rowspan=1 > Alan Walker, K-391 and CORSAK </td><td colspan=1 rowspan=1 > Alexander Zarate Frez </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=5 rowspan=1 > As featured artist </th></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > 2018 </td><th class="highlighted"  colspan=1 rowspan=1 > "San Francisco" </th><td class="highlighted"  colspan=1 rowspan=1 > Galantis </td><td colspan=1 rowspan=1 > Dano Cerny </td><td colspan=1 rowspan=1 >  </td></tr>
<tr> <th colspan=5 rowspan=1 > Guest appearances </th></tr>
<tr> <td colspan=1 rowspan=1 > 2015 </td><th colspan=1 rowspan=1 > "Believe" </th><td colspan=1 rowspan=1 > Shawn Mendes </td><td colspan=1 rowspan=1 > Jake Kasdan </td><td colspan=1 rowspan=1 >  </td></tr>
</table>
Question:
What was Carson featured in 2018?
Answer:
In 2018, Carson was featured in R3hab's "Rumors", Alan Walker's "Different World" and Galantis's "San Francisco".