Answer:
The correct answer is option b. "Because insiders sometimes create threats after incidents at their places of employment".
Step-by-step explanation:
Insider threats are malicious actions originated within the targeted organization. One of the most common sources of insider threats come from former employees that had access to sensitive information, specially when the former employees were laid off and could have resentment to the organization. In this example the targeted organization is a large department store that has recently laid off many employees, situation that makes very likely that the security breach of credit card information came from an insider threat.