The fermentation of starch to give alcohol occurs mainly with the help of :

Options

A. `O_(2)`
B. Air
C. `CO_(2)`
D. Enzymes

Answer

To solve the question regarding the fermentation of starch to give alcohol, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Fermentation**:
- Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol using microorganisms, typically yeast or bacteria, under anaerobic conditions (absence of oxygen).

2. **Identifying the Substrate**:
- In this case, the substrate is starch, which is a polysaccharide made up of glucose units. Starch needs to be broken down into simpler sugars before it can be fermented to alcohol.

3. **Role of Enzymes**:
- The conversion of starch into simpler sugars (like glucose) is facilitated by enzymes. Specifically, enzymes such as amylase break down starch into maltose and then further into glucose.

4. **Fermentation Process**:
- Once starch is converted into glucose, yeast can then ferment glucose to produce alcohol (ethanol) and carbon dioxide. The overall reaction can be summarized as:
\[ \text{Starch} \xrightarrow{\text{Enzymes}} \text{Glucose} \xrightarrow{\text{Yeast}} \text{Alcohol} + \text{CO}_2 \]

5. **Conclusion**:
- Therefore, the fermentation of starch to give alcohol occurs mainly with the help of enzymes.

### Final Answer:
- The correct answer is **Enzymes** (Option E).

---