To archive a survey navigate to 'Surveys & Polls' > 'View'. From here click the 'Archive' button as shown below:
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From here you'll see the following message:
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If you're sure you'd like to archive a survey click 'OK' or otherwise click 'Cancel' to opt out.

Note:
A word of warning, Archiving a survey means that you can no longer find it. So be sure that you want to archive a survey before you do so.