Final answer:
Smooth muscle tissue is responsible for involuntary movements of internal organs, occurring in areas such as the stomach, intestines, and blood vessels, with its activity being autonomic and not consciously controlled.
Step-by-step explanation:
The question seeks to identify the primary function of smooth muscle tissue. The correct answer to the question is that smooth muscle tissue is responsible for the involuntary movement of internal organs. This type of muscle is found in the walls of internal organs such as the stomach, intestines and blood vessels. Since these contractions are not under conscious control, they are considered involuntary, unlike skeletal muscles which are used for voluntary movements. Smooth muscle is also characterized by a non-striated appearance as its actin and myosin are not arranged in a regular pattern like skeletal muscle.