Your grandfather learns that his identity has been stolen, and you suspect that social engineering attacks are responsible. To help him protect his personal information, you tell him how to recognize the most common attacks. From the following list, select all the possible warning signs.
a) Requests for sensitive information via email
b) Unsolicited phone calls asking for personal information
c) Pop-up advertisements asking for credit card details
d) Messages claiming urgent action is required with a link to click on
