A. .ods
B. odt
C. .odf
D. .odp
The default file format in LibreOffice Calc, which is the spreadsheet program in the LibreOffice suite, is the OpenDocument Spreadsheet (ODS) format. ODS is an open standard file format for spreadsheets, and it is part of the OpenDocument Format (ODF) specification. ODS files are XML-based and can be opened by various spreadsheet software that supports the ODF standard.