The longest part of the alimentary canal is the

The food enters the small intestine from the stomach. This is the longest part of the alimentary canal and is fit into a compact space because of extensive coiling. The length of the small intestine differs in various animals depending on the food they eat. Herbivores eating grass need a longer small intestine to allow the cellulose to be digested. Meat is easier to digest, hence carnivores like tigers have a shorter small intestine. Hence, option A is correct.