Which one of the following is also known as antidiuretic hormone?

Options

A. Oxytocin
B. Vasopressin
C. Adrenaline
D. Calcitonin

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the hormone that is also known as antidiuretic hormone (ADH).

2. **Identifying the Options**: The options provided are:
- Oxytocin
- Vasopressin
- Adrenaline
- Calcitonin

3. **Analyzing Each Option**:
- **Oxytocin**: This hormone is involved in childbirth and lactation, stimulating uterine contractions and milk ejection. It is not known as antidiuretic hormone.
- **Vasopressin**: This hormone is indeed known as antidiuretic hormone. It is produced in the hypothalamus and released from the posterior pituitary gland. Its primary function is to promote water reabsorption in the kidneys, thus reducing urine output.
- **Adrenaline**: Also known as epinephrine, this hormone is released during stress and is responsible for the "fight or flight" response. It is not related to water reabsorption.
- **Calcitonin**: This hormone is produced by the thyroid gland and helps regulate calcium levels in the blood. It does not have a role in water retention.

4. **Conclusion**: Based on the analysis, the correct answer is **Vasopressin**, which is the hormone also known as antidiuretic hormone.

**Final Answer**: Vasopressin

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