You can delete individual or multiple responses from the Responses tab under the Report section of your survey.

To delete a single response:

• Go to Report → Responses.
• Locate the response you want to remove.
• Click the Delete icon available in the Action column.
  

To delete multiple responses:

• Select the checkbox beside the required responses.
• Click the Delete button displayed at the top of the table.

To delete all responses on the current page:

• Use the checkbox in the table header to select all visible responses
  
• Or, select all the responses.
• Click Delete to remove them together.