Parts of the alimentary canal in descending order is -
1. Mouth is the first part of the alimentary canal. It has a tongue and 32 teeth and salivary glands, which helps in digestion. Teeth breaks the food into small fragments saliva starts digestion of starch in food and make the food into bolus which is easy for swallowing.
2. Oesophagus is also known as the food pipe. It is a muscular tube which moves the bolus from mouth to stomach.
3. Stomach is a muscular, hollow, dilated part of the digestive system. It secretes protein-digesting enzymes called proteases, pepsin and strong acids to aid in food digestion.
4. Intestine is most important part of the digestive system where much of the digestion and absorption of food takes place and following large intestine. The small intestine is composed of a duodenum, jejunum, and ileum. The large intestine also called the colon or the large bowel. Water is absorbed here and the remaining waste material is stored as feces before being removed by defecation. Thus, the correct answer is option A.