Which of the following is NOT considered a preventive Independent Protection Layer (IPL)?

The answer is correct because a dike is primarily a physical barrier designed to control or contain water, preventing flooding or the spread of hazardous materials, rather than serving as an independent protection layer focusing on risk prevention.

In the context of Layer of Protection Analysis (LOPA), Independent Protection Layers are designed to reduce the likelihood of an event occurring or mitigate its consequences and must operate independently from other protections. While a dike offers a form of protection, it is not considered an IPL since it functions more as a containment method rather than a proactive measure aimed at preventing a hazardous event.

On the other hand, a fire alarm system, safety training program, and security guard all fit the criteria of preventive Independent Protection Layers. Each of these options enhances safety by allowing for detection, preparedness, and immediate response to potential threats, thus effectively contributing to risk reduction.