In a Type 4 system, what occurs when the high level alarm is triggered?

In a Type 4 system, when the high-level alarm is triggered, a light indicator is activated to alert operators that the fuel level has reached a critical point. This visual warning is essential for ensuring that personnel are aware of the situation and can take appropriate action to prevent overfilling, which could lead to spills or other hazardous conditions.

Activating a light indicator serves as a key safety feature within the system, helping maintain operational awareness. It ensures that those monitoring the system are alerted promptly, allowing them to respond before potential issues escalate. This proactive approach is critical for maintaining compliance with safety regulations and protecting environmental integrity.

Other outcomes, such as halting the fueling process or redirecting fuel flow, may be part of a comprehensive response protocol; however, the immediate response when the high-level alarm goes off is the activation of the visual alert system, making option B the most appropriate answer.