The female sex hormone is

Options

A. Estrogen
B. Androgen
C. Insulin
D. Adrenline

Answer

**Step-by-Step Solution:**

1. **Understanding Hormones**: Hormones are natural substances produced and secreted in the body that perform various functions, including regulating reproduction.

2. **Identifying the Options**: The question provides four options: estrogen, androgen, insulin, and adrenaline. We need to determine which of these is the female sex hormone.

3. **Analyzing Each Option**:
- **Estrogen**: This is identified as the major sex hormone in females. It is produced by ovarian follicles and is responsible for stimulating the development of secondary sex organs in females.
- **Androgen**: This is a type of sex hormone produced by the adrenal cortex. It primarily stimulates protein deposition in muscles and nitrogen retention, but it is more associated with male characteristics.
- **Insulin**: This hormone is secreted by the beta cells of the islets of Langerhans in the pancreas and is primarily involved in regulating blood glucose levels, not reproduction.
- **Adrenaline**: Known as the emergency hormone, it is secreted by the adrenal medulla during stress and helps maintain homeostasis, but it is not a sex hormone.

4. **Conclusion**: After evaluating all the options, the female sex hormone is confirmed to be **estrogen**.

**Final Answer**: The female sex hormone is **estrogen**.

---