An antifertility steroid is
(a) Diosgenin
(b) Cortisol
(c) Estradiol
(d) Progesterone

Options

A. Diosgenin
B. Cortisol
C. Estradiol
D. Progesterone

Answer

To determine which of the given options is an antifertility steroid, we can analyze each option based on their known functions and classifications.

### Step-by-Step Solution:

1. **Understanding Antifertility Steroids**:
- Antifertility steroids are substances that can prevent or control pregnancy. They are often used in contraceptives and can influence hormonal levels related to reproduction.

2. **Evaluating Each Option**:
- **(a) Diosgenin**: Diosgenin is a steroid that is derived from plants and is known for its use in the synthesis of various contraceptives. It has antifertility properties and is often used in the production of oral contraceptives.
- **(b) Cortisol**: Cortisol is a steroid hormone produced by the adrenal glands. It is primarily involved in the stress response and metabolism regulation, not in antifertility.
- **(c) Estradiol**: Estradiol is a form of estrogen, a hormone that plays a crucial role in the menstrual cycle and reproductive system. While it is involved in fertility, it is not classified as an antifertility steroid.
- **(d) Progesterone**: Progesterone is another hormone that plays a significant role in the menstrual cycle and pregnancy. It helps maintain pregnancy but does not have antifertility properties.

3. **Conclusion**:
- Based on the analysis, the correct answer is **(a) Diosgenin**, as it is recognized for its antifertility properties and is used in contraceptive formulations.

### Final Answer:
The antifertility steroid is **(a) Diosgenin**.

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