Dear student,

According to your question and taking into consideration that you want to know about muscle fibres. So, here it is-

The main function of the muscle fibres is to exhibit peristalsis. It occurs in tubular viscera . The autonomous nervous system takes control of these muscle fibres.

Hii!
Sorry, but your question seems incomplete. You haven't mentioned any relevant details or tags with the question which help us understand the problem. You may have provided options or specified whether it's any motion you are asking about or the layers of gut. Hence, please restructure your question and ask again including the necessary details.
Hope you understand.
Good luck!