Vasopressin is concerned with

Options

A. General metabolism
B. Regulation of heart beat
C. Urine formation
D. Child birth

Explanation

**Step-by-Step Solution:**

1. **Identify the Hormone**: The question asks about vasopressin, which is also known as antidiuretic hormone (ADH).

2. **Understand the Source**: Vasopressin is produced in the posterior pituitary gland, also referred to as the neurohypophysis.

3. **Determine the Function**: The primary function of vasopressin (ADH) is to regulate water balance in the body. It does this by promoting the reabsorption of water in the kidneys.

4. **Link to Urine Formation**: By increasing water reabsorption, vasopressin helps to concentrate urine, which means it plays a crucial role in urine formation.

5. **Evaluate the Options**: The options provided in the question are:
- General metabolism
- Regulation of heartbeat
- Urine formation
- Childbirth

6. **Select the Correct Answer**: Since vasopressin is primarily concerned with the reabsorption of water and thus urine formation, the correct answer is "urine formation".

**Final Answer**: Vasopressin is concerned with **urine formation**.

---