One of the following is not a respiratory pigment.

Options

A. (a) Hemoglobin
B. (b) Chlorocruorin
C. (c) Hemocyanin
D. (d) Hemozoin

Answer

**Step-by-Step Solution:**

1. **Understanding Respiratory Pigments**: Respiratory pigments are metalloproteins that play a crucial role in the transport of oxygen and carbon dioxide in the blood. They are responsible for the color of the blood and also help in oxygen storage and maintaining the pH of the blood.

2. **Identifying Common Respiratory Pigments**:
- **Hemoglobin**: Found in mammals, it contains iron and is a primary respiratory pigment responsible for oxygen transport.
- **Chlorocruorin**: Present in some annelids, it also contains iron and functions similarly to hemoglobin.
- **Hemocyanin**: Found in mollusks and some arthropods, it contains copper instead of iron and serves as a respiratory pigment.

3. **Analyzing the Options**:
- **Option A: Hemoglobin** - This is a well-known respiratory pigment.
- **Option B: Chlorocruorin** - This is also a respiratory pigment.
- **Option C: Hemocyanin** - This is another example of a respiratory pigment.
- **Option D: Dehemoglobin** - This is not a respiratory pigment; it is a byproduct of hemoglobin breakdown and is associated with malarial infections.

4. **Conclusion**: Among the options provided, **Dehemoglobin** is not a respiratory pigment. Therefore, the correct answer to the question is **Dehemoglobin**.

**Final Answer**: Dehemoglobin is not a respiratory pigment.

---