The major function of corpus luteum is

Options

A. Excretory
B. Digestive
C. Nervous
D. Endocrine.

Answer

### Step-by-Step Solution:

1. **Understanding the Corpus Luteum**:
- The corpus luteum is a structure that forms in the ovary after ovulation, which is the release of an egg from a mature follicle.

2. **Formation of Corpus Luteum**:
- After the egg is released, the mature follicle transforms into the corpus luteum. This is a crucial phase in the menstrual cycle.

3. **Two Possible Scenarios**:
- After the formation of the corpus luteum, there are two possible outcomes:
- **No Fertilization**: If the egg is not fertilized, the corpus luteum will degenerate.
- **Fertilization Occurs**: If the egg is fertilized, the corpus luteum will persist.

4. **Hormonal Function**:
- In the case of fertilization, the corpus luteum secretes hormones, primarily progesterone and estrogen. These hormones are essential for maintaining the pregnancy.

5. **Endocrine Function**:
- Since the corpus luteum releases hormones directly into the bloodstream, it functions as an endocrine gland. This is its major role.

6. **Elimination of Other Options**:
- The other options (excretory, digestive, nervous) can be ruled out:
- **Excretory**: The corpus luteum does not remove waste products.
- **Digestive**: It is not involved in digestion or breakdown of molecules.
- **Nervous**: There is no transmission of impulses associated with the corpus luteum.

7. **Conclusion**:
- Therefore, the major function of the corpus luteum is endocrine, making the correct answer option D.