The flatworm's muscular system consists of two layers of muscle.
The muscular layer (muscular coat, muscular fibres, muscular propria, muscularis externa) is a part of the muscle in multiple organs in the vertebrate body, adjacent to the submucosa. It is liable for gut movement such as peristalsis.
Thus, It consists of two layers of muscle.
To learn more about two muscle layers click here:
https://brainly.com/question/9383578