All physical barriers are designed to discourage three types of penetration.

Physical barriers are designed to defend against three main penetration techniques:

Stealth: Unauthorized entry without detection.

Deception: Gaining access through trickery or impersonation.

Force: Physical breaching of barriers or using tools or vehicles to gain entry.

Security systems are designed to detect and delay each of these methods effectively.

A and B mix categories inaccurately.

C (Vehicle) is a tool/method of force, not a category on its own.