Simon is having trouble using linked workbooks, so he consults his colleague Brooke for help.Simon tells Brooke that when he attempts to open a workbook, the Edit Links dialog box appears with the message "This workbook contains one or more links that cannot be updated." Brooke suggests several possible causes of this error message. Which of the following is a possible cause?
a. the workbook was sent to him without links
b. one of the workbook's source files was edited
c. one of the workbook's source files was copied to a different folder
d. one of the workbook's source files was replaced with an updated file of the same name

According to the question, as per message of no presence of link on Edit links dialog box it indicates that links were not present workbook and thus the directed page of workbook cannot be opened .Brooke should suggest about workbook does not have links.

Other options are incorrect because editing is not done in workbook file of source,they are neither copied nor replaced or updated with similar name. Thus, the correct option is option(a).