Repair of endometrium is undertaken by

Options

A. LH
B. FSH
C. estrogen
D. prolactin.

Explanation

To answer the question "Repair of endometrium is undertaken by," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Endometrium**:
- The endometrium is the innermost lining of the uterus, which plays a crucial role in the menstrual cycle. It undergoes cyclic changes in response to hormonal fluctuations.

**Hint**: Remember that the endometrium is the layer that thickens and sheds during the menstrual cycle.

2. **Hormonal Influence**:
- The repair and proliferation of the endometrium are influenced by various hormones. The key hormones involved in the menstrual cycle include Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH), estrogen, and progesterone.

**Hint**: Consider which hormones are primarily responsible for the growth and repair of the uterine lining.

3. **Role of Estrogen**:
- Estrogen is secreted by the ovarian follicles under the influence of FSH. It is primarily responsible for the proliferation of the endometrial lining after menstruation.

**Hint**: Estrogen is often associated with the growth and repair of tissues, especially in the reproductive system.

4. **Identifying the Correct Answer**:
- Given the options:
1. LH
2. FSH
3. Estrogen
4. Prolactin
- The hormone that directly facilitates the repair of the endometrium is estrogen.

**Hint**: Focus on which hormone is specifically linked to the regeneration of the endometrial lining.

5. **Conclusion**:
- Therefore, the correct answer to the question is **option 3: Estrogen**.

### Final Answer:
The repair of the endometrium is undertaken by **Estrogen**.