Final answer:
The muscularis externa is the layer of the digestive tract that contains the effectors for digestive propulsion.
Step-by-step explanation:
The layer of the digestive tract that contains the effectors for digestive propulsion is the muscularis externa. The muscularis externa is the third layer of the alimentary canal and is responsible for the contractions that promote mechanical digestion, expose food to digestive chemicals, and move the food along the canal. It consists of smooth muscle layers, including an inner circular layer and an outer longitudinal layer.