Sublimation is involved in

Options

A. incense stick and odonil.
B. camphor and incense stick.
C. perfume and odonil.
D. naphthalene balls and camphor.

Explanation

### Step-by-Step Solution:

1. **Understanding Sublimation**:
- Sublimation is the process where a solid changes directly into a gas without passing through the liquid phase.

2. **Analyzing the Options**:
- We have four options to consider:
1. Incense stick and odonil
2. Camphor and incense stick
3. Perfume and odonil
4. Naphthalene balls and camphor

3. **Evaluating Each Option**:
- **Option 1: Incense stick and odonil**:
- Incense sticks primarily use diffusion to spread their fragrance, not sublimation. Odonil, however, does undergo sublimation. This option is incorrect.

- **Option 2: Camphor and incense stick**:
- Camphor does undergo sublimation, but incense sticks use diffusion. Therefore, this option is also incorrect.

- **Option 3: Perfume and odonil**:
- Perfume uses diffusion to spread its scent, while odonil sublimates. Hence, this option is incorrect as well.

- **Option 4: Naphthalene balls and camphor**:
- Both naphthalene balls and camphor undergo sublimation. They change directly from solid to gas. This option is correct.

4. **Conclusion**:
- The correct answer is **Option 4: Naphthalene balls and camphor**.