Final answer:
The muscularis layer, also known as the muscularis externa, produces the peristaltic contractions that propel food through the alimentary canal. Therefore, the correct option is B.
Step-by-step explanation:
The contractions of peristalsis within the alimentary canal are produced by the muscularis layer. This layer is also known as the muscularis externa. In the small intestine, the muscularis is made up of a double layer of smooth muscle, which includes an inner circular layer and an outer longitudinal layer. These muscle layers work in a coordinated fashion to produce the rhythmic contractions that propel food through the digestive system. Additionally, in certain parts of the alimentary canal such as the stomach, there is a third layer of muscle called the oblique muscle that aids in the mechanical digestion of food.