Which type of muscle is found in the walls of internal organs like the intestines?

Smooth muscle is the correct answer because it is specifically designed for involuntary, automated processes that occur in the walls of internal organs, such as the intestines, blood vessels, and the bladder. This type of muscle is not under conscious control and enables functions such as peristalsis, which moves food through the digestive tract, and regulates blood flow.

Unlike skeletal muscle, which is associated with voluntary movement and is striated, smooth muscle fibers are non-striated, meaning they do not have the banded appearance of skeletal muscle, and they can contract more slowly and sustain longer contractions. Cardiac muscle, while also striated like skeletal muscle, is found only in the heart and is responsible for pumping blood. Striated muscle is a general term that could refer to both skeletal and cardiac muscle, but it does not specifically indicate the muscle type found in the walls of internal organs.