Jacky Correa is an accountant with a large accounting firm. The firm has a very strict policy of requiring all users to change their passwords every sixty days. In early June, Jacky received an email from the firm that explained that there had been an error updating his password and that provided a link to a Web site with instructions for re-entering his password. Something about the email made Jacky suspicious, so he called the firm's information technology department and found that the email was fictitious. The email was an example of

a.

social engineering.

b.

piggybacking.

c.

phishing.

d.

spamming.