The correct answer is "<span>a layer of smooth </span><span>muscle".
</span>In an individual's mouth, gut, and the small intestine, the mucosa, which holds tiny glands, which secrete juices in order to assist in digesting food<span>. The </span>digestive<span> tract also holds a layer of smooth </span>muscle, which <span>aids in breaking down </span>food<span> and move it along the digestive tract.</span>
