Answer:
[tex]\boxed {\tt Saliva}[/tex]
Explanation:
The digestive tract and process of digestion actually begin with the mouth. Teeth help break the food up into smaller pieces that are simpler to absorb and digest. Saliva helps moisten the food so it is easier to swallow, but it also contains an enzyme called amylase. This enzyme helps break down carbohydrates into simple sugars and begins the digestion of carbohydrates.
Therefore, the best answer choice is C. saliva.
