You own a small company in a remote industrial area. Lately, the alarm regularly goes off in the middle of the night. It takes quite a bit of time to respond to it and it seems to be a false alarm every time. You decide to set up a hidden camera. What is such a measure called?

A.
Detective measure

B.
Preventive measure

C.
Repressive measure

Explanation:
Detective countermeasures are aimed at detecting incidents.