The layers of the alimentary canal are given from the inside to the outside.

• A
  Mucosa $\rightarrow$ Submucosa $\rightarrow$ Muscularis $\rightarrow$ Serosa
• B
  Serosa $\rightarrow$ Muscularis $\rightarrow$ Submucosa $\rightarrow$ Mucosa
• C
  Submucosa $\rightarrow$ Mucosa $\rightarrow$ Muscularis $\rightarrow$ Serosa
• D
  Serosa $\rightarrow$ Muscularis $\rightarrow$ Mucosa $\rightarrow$ Submucosa