Carotenoids are

Options

A. glycoproteins
B. hydrocarbons
C. Polysaccharides
D. lipoproteins

Answer

### Step-by-Step Solution:

1. **Definition of Carotenoids**:
Carotenoids are pigments found in plants, algae, and photosynthetic bacteria. They are responsible for the bright yellow, red, and orange colors in many fruits and vegetables.

2. **Classification**:
Carotenoids are classified as a type of glycoprotein. They are not hydrocarbons, polysaccharides, or lipoproteins.

3. **Function**:
In addition to providing color, carotenoids serve important functions such as acting as antioxidants in humans. This means they help protect cells from damage caused by free radicals.

4. **Variety**:
There are over 600 different types of carotenoids, which contribute to the diversity of colors and functions in various organisms.

5. **Conclusion**:
Based on the classification and characteristics discussed, the correct answer to the question "Carotenoids are" is that they are glycoproteins.

### Final Answer:
Carotenoids are glycoproteins.

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