Answer:
Take regular backups ( A )
Step-by-step explanation:
Spreadsheets are a form of database management system, this means that important data is been stored, updated and changed there. one of the best ways to do this efficiently without complete or partial loss of stored,updated or changed data is to ensure regular backups of the spreadsheets so that in a case of loss of data on the computer. the backup source can be queried for the information been backed up/stored in it,such backup devices can be an external hard drive.
telling her colleagues about the file location can not help her recover her data when they are lost because the spreadsheet is stored electronically in her computer and not in physical location, making duplicate copies on the same computer won't help as well because if the computer fails the duplicate copy will be lost as well