Which of the following is /are correct statement(s) regarding preparation of cake and pastries ?
I. Baking soda is used.
II. Caustic soda is used.
III. Baking soda is used because on heating it produces `CO_2` bubbles.

Options

A. I and II
B. I and III
C. II and III
D. Only III

Answer

To solve the question regarding the preparation of cake and pastries and to determine which statements are correct, let's analyze each statement step-by-step.

### Step 1: Analyze Statement I
**Statement I:** Baking soda is used.

- **Explanation:** Baking soda, chemically known as sodium bicarbonate (NaHCO3), is indeed used in baking. It acts as a leavening agent, which helps the cake and pastries rise by producing carbon dioxide gas when it is heated or combined with an acid.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze Statement II
**Statement II:** Caustic soda is used.

- **Explanation:** Caustic soda, or sodium hydroxide (NaOH), is not used in the preparation of cakes and pastries. It is a strong base and can be harmful if ingested. It does not serve any purpose in baking and is not suitable for food preparation.

**Conclusion:** This statement is **incorrect**.

### Step 3: Analyze Statement III
**Statement III:** Baking soda is used because on heating it produces CO2 bubbles.

- **Explanation:** When baking soda is heated, it decomposes to produce carbon dioxide gas (CO2), which forms bubbles in the batter. These bubbles expand during baking, causing the cake or pastry to rise and become fluffy.

**Conclusion:** This statement is **correct**.

### Final Conclusion
Based on the analysis:
- Statement I is correct.
- Statement II is incorrect.
- Statement III is correct.

Thus, the correct statements regarding the preparation of cake and pastries are **I and III**.

### Summary of Correct Statements:
- **Correct Statements:** I and III
- **Incorrect Statement:** II