The hormone that promotes female flowers in cucumbers is:

Options

A. Auxins
B. Gibberellins
C. Cytokinins
D. Ethephon

Answer

To solve the question regarding the hormone that promotes female flowers in cucumbers, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Question**: The question asks for the hormone responsible for promoting female flowers in cucumbers.

2. **Understand the Role of Hormones in Plants**: Different hormones in plants have specific roles. For instance, auxins promote cell elongation, gibberellins are involved in seed germination and growth, and cytokinins promote cell division.

3. **Focus on Ethylene**: Ethylene is a plant hormone known for its role in fruit ripening and flower development. It is particularly important in the promotion of female flowers in certain plants, including cucumbers.

4. **Consider Other Options**:
- Auxins are primarily involved in growth and elongation, not specifically in promoting female flowers.
- Gibberellins are mainly associated with seed germination and stem elongation.
- Cytokinins are involved in cell division and growth but do not specifically promote female flower development.

5. **Conclude with the Correct Answer**: Since ethylene is the hormone that promotes the formation of female flowers in cucumbers, the correct answer is ethylene.

### Final Answer:
The hormone that promotes female flowers in cucumbers is **ethylene**.