- The autonomic nervous system (ANS) is a critical part of the nervous system responsible for regulating involuntary bodily functions, such as heart rate, digestion, respiratory rate, and glandular activity.
- The ANS is primarily divided into two main components: the sympathetic and parasympathetic nervous systems.

- The sympathetic nervous system is often described as the "fight or flight" system because it prepares the body to respond to stressful or emergency situations by increasing heart rate, dilating airways, and mobilizing energy stores.
- The parasympathetic nervous system, on the other hand, is known as the "rest and digest" system, as it promotes relaxation, energy conservation, and maintenance of bodily functions during restful states.

These two components work in a complementary manner to maintain homeostasis and coordinate the body's automatic responses to changing internal and external environments.

Other options mentioned are related but do not represent the primary subdivisions of the ANS:
- Option 2 (Somatic and autonomic) reflects the division of the overall peripheral nervous system into voluntary (somatic) and involuntary (autonomic) parts.
- Option 3 (Central and peripheral) refers to the overall nervous system division.
- Option 4 (Voluntary and involuntary) describes types of control but is not specific to the ANS subdivisions.

Therefore, the correct answer is Sympathetic and parasympathetic.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th Edition, Chapter 15: Autonomic Nervous System