Matt, an account manager, arrives at work early in the morning and cannot log into his
workstation. He calls the help desk an hour later to open a trouble ticket, but they tell him there is

nothing wrong with his account. Matt tries his login once more and is granted access. Which of the
following control types BEST explains this anomaly?

A.
Discretionary access control

B.
Time of day restrictions

C.
Separation of duties

D.
Single sign-on