**Core Concept**
The limbic system is a complex neural network in the brain that plays a crucial role in emotional processing, motivation, and memory formation. It is involved in the regulation of emotions, such as fear, anger, and aggression, as well as in the formation of emotional associations and memories.

**Why the Correct Answer is Right**
The limbic system is responsible for integrating sensory information from various sources, including the senses, and modulating the emotional response to that information. This is achieved through the interaction of various structures, including the hippocampus, amygdala, and hypothalamus, which work together to process and consolidate emotional memories. The limbic system also influences motivation and reward processing, as seen in the release of dopamine in response to pleasurable stimuli.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because the limbic system is not primarily involved in the regulation of voluntary motor movements.
**Option B:** This is incorrect because the limbic system is not directly involved in the processing of language or speech.
**Option C:** This is incorrect because the limbic system is not primarily involved in the regulation of cognitive functions, such as attention or executive functions.

**Clinical Pearl / High-Yield Fact**
Damage to the limbic system, particularly the hippocampus, can lead to anterograde amnesia, a condition characterized by the inability to form new memories. This is often seen in patients with temporal lobe epilepsy or those who have suffered a traumatic brain injury.

**Correct Answer:** C. Memory formation and emotional processing.