Final answer:
The Hippocampus is part of the Limbic System, which is responsible for emotion regulation, fear, and memory formation. The hippocampus is part of the limbic system, a connected set of structures in the brain that regulates emotion and behavior.
Step-by-step explanation:
The organ that is part of the Limbic System is C) Hippocampus. The Limbic System plays a crucial role in regulating emotions, behaviors related to fear and motivation, and is also pivotal in the formation of memory. This complex of interconnected brain structures includes the amygdala, cingulate gyrus, and parts of the thalamus and hypothalamus, alongside the mentioned hippocampus.