What can trigger the activation of the ABS system?

The activation of the Anti-lock Braking System (ABS) is primarily triggered when a vehicle experiences sudden braking, especially on slippery surfaces. This system is designed to prevent the wheels from locking up, which can lead to a loss of steering control. When a driver brakes suddenly in conditions where traction is reduced—such as on wet or icy roads—the ABS will engage to modulate the brake pressure, allowing the wheels to continue rotating. This helps maintain steering control while slowing down.

In contrast, accelerating sharply, driving at low speeds, or maintaining a constant speed typically do not activate the ABS because these actions do not involve braking hard enough to require the system’s intervention. Therefore, the condition described in the correct answer is the most relevant scenario for how ABS operates in real-world driving situations.