Innermost zone is the:

Options

A. hottest part
B. moderately hot part
C. least hot part
D. cold part

Explanation

To answer the question "Innermost zone is the:", we need to analyze the structure of a candle flame. The candle flame has different zones, each with varying temperatures and characteristics.

### Step-by-Step Solution:

1. **Understanding the Structure of a Candle Flame**:
- A candle flame consists of several zones: the outer zone, the inner zone, and the core.
- The outer zone is the part that is typically blue and is the hottest part of the flame.

2. **Identifying the Zones**:
- The **outer zone** is the hottest part of the flame, where combustion is most efficient.
- The **inner zone** is the part of the flame that is moderately hot.
- The **innermost zone** is the part of the flame that is yellow and is the least hot.

3. **Determining the Innermost Zone**:
- The innermost zone of the candle flame is characterized by a yellow color, indicating that it is the least hot part of the flame.
- This zone is where incomplete combustion occurs, leading to the yellow color due to the presence of soot particles.

4. **Conclusion**:
- Therefore, the innermost zone of the candle flame is the part that is the least hot, which is often referred to as the "inner zone" or "core" of the flame.

5. **Final Answer**:
- The innermost zone is the "least hot" part of the flame.