Why of the following hormones plays a very important role in the regulation of diurnal rhythm of our body ?

Options

A. Melatonin
B. ADH
C. Gonadotropin
D. Androgen

Answer

To solve the question about which hormone plays a very important role in the regulation of the diurnal rhythm of our body, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which hormone is crucial for regulating the diurnal rhythm, which refers to the natural cycle of physical, mental, and behavioral changes in a 24-hour cycle, primarily influenced by light and darkness.

2. **Identify the Options**: The options provided are:
- A) Melatonin
- B) ADH (Antidiuretic Hormone)
- C) Gonadotropin
- D) Androgen

3. **Evaluate Each Option**:
- **Option A: Melatonin**: This hormone is produced by the pineal gland in response to darkness and is known to regulate sleep-wake cycles, making it a key player in the diurnal rhythm.
- **Option B: ADH**: This hormone primarily regulates water balance and blood pressure, not directly involved in the diurnal rhythm.
- **Option C: Gonadotropin**: This hormone stimulates the gonads to produce sex hormones but does not play a significant role in regulating the diurnal rhythm.
- **Option D: Androgen**: These hormones are important for male reproductive functions but are not directly related to the diurnal rhythm.

4. **Conclusion**: After evaluating all options, it is clear that **Melatonin** (Option A) is the hormone that plays a very important role in the regulation of the diurnal rhythm of our body.

### Final Answer:
The hormone that plays a very important role in the regulation of the diurnal rhythm of our body is **Melatonin**.

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