Hormone is

Options

A. Enzyme
B. Chemical messenger
C. Excretory product
D. Glandular secretion.

Answer

### Step-by-Step Solution:

1. **Understanding Hormones**:
- Hormones are defined as non-nutrient chemicals produced in the body in trace amounts. They play a crucial role in regulating physiological processes.

2. **Production of Hormones**:
- Hormones are produced by specialized glands known as endocrine glands. These glands are ductless, meaning they release hormones directly into the bloodstream.

3. **Function of Hormones**:
- Once released into the bloodstream, hormones travel to various target organs and tissues, where they exert their effects to bring about physiological changes necessary for maintaining homeostasis.

4. **Analyzing the Options**:
- **Option A: Enzyme** - Incorrect, as enzymes are biological catalysts that facilitate biochemical reactions, not hormones.
- **Option B: Chemical Messenger** - Correct, as hormones act as chemical messengers that transmit signals to different parts of the body.
- **Option C: Excretory Product** - Incorrect, as excretory products are waste materials that the body needs to eliminate, while hormones are essential for bodily functions.
- **Option D: Glandular Secretion** - Incorrect, as while hormones are secreted by glands, the term "glandular secretion" is too broad and does not specifically define hormones.

5. **Conclusion**:
- Based on the analysis, the correct answer is **Option B: Chemical Messenger**.