## Core Concept
The process of starch hydrolysis in the mouth involves the breakdown of complex carbohydrates into simpler sugars. This initial step in carbohydrate digestion occurs in the oral cavity. The enzyme responsible for this process is specifically adapted to work in the mouth's environment.

## Why the Correct Answer is Right
The correct answer, **.**, refers to **salivary amylase**. Salivary amylase is an enzyme produced by the salivary glands that is secreted into the mouth during chewing. It catalyzes the hydrolysis of starch, a polysaccharide, into shorter-chain sugars like maltose and dextrins. This process begins the digestion of carbohydrates, making it easier for further enzymatic actions to occur in the gastrointestinal tract.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it does not specify an enzyme known for carbohydrate digestion in the mouth.
- **Option B:** This option is incorrect because, although it might relate to digestion, it is not the specific enzyme responsible for starch hydrolysis in the mouth.
- **Option C:** This option is incorrect because it does not accurately represent the enzyme responsible for the initial breakdown of starch in the oral cavity.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **salivary amylase** is inactivated by stomach acid (hydrochloric acid) in the stomach, which means its action is limited to the mouth and possibly the upper part of the esophagus before being swallowed. This fact highlights the importance of the oral cavity in initiating carbohydrate digestion.

## Correct Answer Line
**Correct Answer: B. salivary amylase**