## Core Concept
The limbic system is a complex set of structures in the brain that play a crucial role in emotions, motivation, and memory. It is involved in the processing of sensory information and the regulation of emotional responses. The limbic system includes several key structures such as the hippocampus, amygdala, and hypothalamus.

## Why the Correct Answer is Right
The correct answer, although not explicitly provided, would relate to a well-established fact about the limbic system. Typically, a true statement might involve the role of a specific structure within the limbic system, such as the hippocampus in memory formation or the amygdala in emotional processing. For instance, a correct statement could be that the limbic system is crucial for emotional regulation and memory, particularly the formation of new memories.

## Why Each Wrong Option is Incorrect
- **Option A:** Without the specific details of Option A, it's challenging to provide a direct refutation. However, if Option A suggested that the limbic system is primarily involved in motor control, it would be incorrect because motor control is primarily associated with other brain regions such as the cerebellum and the motor cortex.
- **Option B:** Similarly, if Option B proposed that the limbic system is solely responsible for sensory processing, it would be incorrect because, while the limbic system does process sensory information, especially in the context of emotional and motivational states, primary sensory processing occurs in sensory cortices.
- **Option C:** If Option C stated that the limbic system is not involved in emotional regulation, it would be incorrect because a significant body of evidence supports the limbic system's, particularly the amygdala's, critical role in processing emotions.
- **Option D:** If Option D suggested that the limbic system only includes the cerebral cortex, it would be incorrect because the limbic system encompasses a range of subcortical structures in addition to certain cortical areas.

## Clinical Pearl / High-Yield Fact
A key point to remember is that damage to the limbic system, particularly to structures like the hippocampus, can lead to profound memory impairments, as seen in conditions like Alzheimer's disease. The limbic system's role in emotion and motivation also makes it a critical area of study in psychiatric disorders.

## Correct Answer: D.