The Muscular System is described as:

• A. Allows Manipulation of the Environment, Locomotion, and Facial Expression. Maintains Posture, and Produces Heat.
• B. Transmits Neural Signals to Glands
• C. Circulates Blood
• D. Regulates Hormones

Answer: (A)

Movement and heat production are primary roles of the muscular system. Skeletal muscles enable manipulation of the environment, locomotion, and facial expressions by moving bones and facial skin. They also sustain posture by contracting to counteract gravity, keeping the body upright and stable. Additionally, muscle contractions generate heat as a byproduct of metabolism, helping maintain body temperature.

Transmitting neural signals to glands belongs to the nervous system, circulating blood to the body to the cardiovascular system, and regulating hormones to the endocrine system. The description aligns with the muscular system because it emphasizes movement, posture, and heat production.