Assertion-Reason relation :
Visceral muscles are also called smooth, non-striated, non-striped or involuntary muscles.
These muscles are found in the visceral organs and hence are called visceral muscles. For example, smooth muscles are found in the digestive tract through which food gets transported. The peristalsis of smooth muscles propels the food along the gut.
Visceral muscles are involuntary, which means they cannot be controlled with our conscious thought.
Visceral muscles also lack striations (alternate light and dark bands are absent) and are hence called non-striated or non-striped muscles.
So, both the assertion and reason are correct. Also, reason is the correct explanation of the assertion.