Which of the following is a steroid hormone ?

Options

A. Progesterone
B. Insulin
C. Thryoxine
D. Oxytocin

Answer

To determine which of the given hormones is a steroid hormone, we need to analyze each option based on their origin and classification.

### Step-by-Step Solution:

1. **Understand what steroid hormones are**:
- Steroid hormones are a class of hormones that are derived from cholesterol. They are lipophilic (fat-soluble) and can easily pass through cell membranes to bind to receptors inside the cell.

2. **Identify the sources of steroid hormones**:
- Steroid hormones are primarily produced by the adrenal glands and gonads (ovaries and testes).

3. **Evaluate the given hormones**:
- **Progesterone**: This hormone is produced by the corpus luteum in the ovaries. Since it is derived from cholesterol and is produced by the gonads, progesterone is classified as a steroid hormone.
- **Insulin**: This hormone is produced by the pancreas. It is a peptide hormone, not derived from cholesterol, and therefore not a steroid hormone.
- **Thyroxine**: This hormone is produced by the thyroid gland. It is an amino acid-derived hormone (specifically from tyrosine) and is not a steroid hormone.
- **Oxytocin**: This hormone is produced by the hypothalamus and secreted by the pituitary gland. It is a peptide hormone and not a steroid hormone.

4. **Conclusion**:
- Among the options provided, **progesterone** is the only steroid hormone.

### Final Answer:
**Progesterone** is a steroid hormone.