A significant amount of progesterone is product by the

Options

A. Corpus luteum
B. testis
C. Placenta
D. Both A and B

Answer

To solve the question "A significant amount of progesterone is produced by the," we will analyze each option provided in the context of biological knowledge regarding progesterone production.

### Step-by-Step Solution:

1. **Understanding Progesterone Production**:
- Progesterone is a hormone that plays a crucial role in the menstrual cycle, pregnancy, and embryogenesis in humans.

2. **Analyzing the Options**:
- **Option A: Corpus Luteum**:
- The corpus luteum is a temporary endocrine structure that forms in the ovary after ovulation. It is known for producing significant amounts of progesterone, which is essential for maintaining the early stages of pregnancy.
- **Conclusion**: This option is correct.

- **Option B: Testis**:
- The testis primarily produces testosterone, but it also produces small amounts of progesterone. In males, progesterone is involved in the synthesis of testosterone and other hormones.
- **Conclusion**: This option is also correct, though the amount of progesterone produced is significantly less compared to the corpus luteum.

- **Option C: Placenta**:
- The placenta is an organ that develops in the uterus during pregnancy. It produces several hormones, including human chorionic gonadotropin (hCG), estrogen, and progesterone. The placenta is a major source of progesterone during pregnancy.
- **Conclusion**: This option is correct as well.

- **Option D: Both A and B**:
- Since both the corpus luteum and the testis produce progesterone, this option is valid. However, it does not account for the placenta, which also produces progesterone.

3. **Final Conclusion**:
- Since the question asks for a significant amount of progesterone, the best answer would include all sources. However, since the options provided do not include a choice that encompasses all three (A, B, and C), the most appropriate answer based on the options given is **Option D: Both A and B**.

### Final Answer:
**Option D: Both A and B**