Which of the following is an extension of a worksheet created in LibreOffice Calc?

In LibreOffice Calc, the extension of a worksheet file is typically ".ods", which stands for Open Document Spreadsheet. This format is part of the Open Document Format (ODF) which is used for various types of office documents including spreadsheets.

Other extensions related to spreadsheet files include ".xls" and ".xlsx" which are used by Microsoft Excel, but the standard for LibreOffice Calc is ".ods". Additionally, ".ots" is the extension for Open Document Spreadsheet templates in LibreOffice.

Therefore, the most common extension for a worksheet created in LibreOffice Calc is .ods.