Number of emails received in one account every day from the day it was created until it was canceled: a. sample b. complete info

The answer is B. Complete information.

A sample means only part of the whole. From the day the email was created till it was cancelled is the whole population. Consider that no mails will no longer go in because it is closed so no more additional information or data will enter that category. So it would be considered as complete. If the situation were to ask from one point to another before it was cancelled it would be considered as a sample. 

Iam not sure , but probably 750 or 7.5