Android : Force exit task that requires authentication when user returns from lock screen

Scenario

From activity A: User presses button that directs them to a pin authentication dialog. If the user enters a valid pin, they are put into activity B. If invalid, they remain in activity A.

From activity B: User navigates to activity C in another application.

User locks the device.

User unlocks the device.

What happens

User is back in activity C.

Desired behavior

User is thrown back into activity A.

Question

How is it possible to launch activity C in such a way that the user is kicked out when they try to return to it from lock screen?

The difficult part here is that I have no control over activity C other than how I send the intent from my application.