Final answer:
The security feature that can cause a mobile device to be completely locked for a period of time if the passcode is entered incorrectly a number of times is the Lockout Policy.
Step-by-step explanation:
The security feature that can cause a mobile device to be completely locked for a period of time if the passcode is entered incorrectly a number of times is the Lockout Policy. When the lockout policy is enabled, a user will be temporarily locked out of their mobile device after a specified number of failed passcode attempts. This helps to prevent unauthorized access to the device and protects user data.