**Core Concept**
The basal ganglia are a group of subcortical structures in the brain involved in motor control and cognition. They play a crucial role in the regulation of voluntary motor movements, procedural learning, routine behaviors or "habits" such as teeth grinding, eye movements, cognition, and emotion.

**Why the Correct Answer is Right**
The basal ganglia are a complex system that includes the caudate nucleus, putamen, globus pallidus, substantia nigra, and subthalamic nucleus. They function by integrating sensory input from the cortex and thalamus to modulate the activity of the motor cortex, ultimately influencing movement and motor planning. The basal ganglia also play a role in the development of habits and procedural memory.

**Why Each Wrong Option is Incorrect**
* **Option A:** This is a vague choice and does not accurately describe a function of the basal ganglia. The basal ganglia are involved in more specific processes such as motor control and habit formation.
* **Option B:** This choice is too broad and could apply to many brain regions, not just the basal ganglia. While the basal ganglia do play a role in cognition, this is not their primary function.
* **Option C:** This choice is incorrect because the basal ganglia are not primarily involved in the regulation of emotional responses. While they do play a role in the processing of emotions, this is not their primary function.

**Clinical Pearl / High-Yield Fact**
The basal ganglia are often affected in movement disorders such as Parkinson's disease, Huntington's disease, and dystonia. Understanding the function of the basal ganglia is critical for diagnosing and treating these conditions.

**Correct Answer: C. Motor control and habit formation.**