What does the autonomic nervous system regulate?

The autonomic nervous system plays a crucial role in regulating involuntary functions within the body. This system is responsible for overseeing processes that occur without conscious control, such as heart rate, blood pressure, digestion, and respiratory rate. By managing these essential functions automatically, the autonomic nervous system maintains homeostasis and ensures that the body's internal environment remains stable despite external changes.

The other options relate to functions that are under voluntary control or require higher cognitive processing. For instance, voluntary muscle movements are managed by the somatic nervous system, while conscious sensory processing and complex problem-solving skills are functions of the central nervous system involving higher brain regions. Therefore, they don't pertain to the autonomic nervous system's responsibilities, making the answer that highlights the regulation of involuntary functions the most accurate choice.