Question

In the scenario in the lab, marina neglected to use a(n) __________ on her smartphone, which meant that anyone could gain immediate access to her contacts and other private information

Answer 1

I believe the answer is: Screen lock

Screen lock in smart phones consisted of  passwords that usually utilize combinations of numbers or pattern, which prevent non-owners to access the phone without the owner's consent
Failing to give correct input for the passwords for several time would cause most phones to be permanently locked.