6) From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen.
A) muscularis externa, serosa, mucosa, and submucosa
B) serosa, mucosa, submucosa, and muscularis externa
C) submucosa, serosa, muscularis externa, and mucosa
D) mucosa, submucosa, muscularis externa, and serosa