Which of the following is a strong post designed to stop a car?

A gate controls authorized entry and exit at a perimeter but is not engineered to physically withstand or stop a moving vehicle attempting to breach it.

A fence defines a perimeter boundary and deters casual intrusion but provides minimal structural resistance against a vehicle driving through it.

A bollard is a robust physical barrier - typically constructed of reinforced steel or concrete - that is installed to prevent vehicle-borne attacks or accidental intrusions into a protected area. Unlike perimeter controls such as fences or gates, bollards are purpose-built and rated for vehicle impact resistance, making them the standard countermeasure against vehicle ramming threats.

Reinforced rebar is a construction material embedded within concrete structures to add tensile strength - it is not a standalone deployable security barrier.