The number of female flowers can be increased by the application of

Options

A. IAA
B. `C_(2)H_(4)`
C. CK
D. All of these

Answer

To solve the question regarding the increase in the number of female flowers through hormonal application, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Question**: The question asks which hormone can increase the number of female flowers in plants.

2. **Review the Options**: The options provided are:
- A) IAA (Indole Acetic Acid)
- B) C2H4 (Ethylene)
- C) CK (Cytokinins)

3. **Understand the Role of Each Hormone**:
- **IAA (Indole Acetic Acid)**: This is a type of auxin that primarily promotes cell elongation and is involved in various growth processes but does not specifically increase female flower production.
- **C2H4 (Ethylene)**: Ethylene is a gaseous plant hormone that plays a crucial role in the development of flowers, particularly in promoting the formation of female flowers.
- **CK (Cytokinins)**: Cytokinins are involved in cell division and can influence various aspects of growth but are not directly linked to increasing female flower production.

4. **Analyze the Role of Ethylene**: Ethylene is known to work in conjunction with auxins. The presence of auxins can enhance the production of ethylene, which in turn promotes the development of female flowers.

5. **Conclusion**: Based on the understanding that ethylene plays a significant role in increasing the number of female flowers, we can conclude that the correct answer is **B) C2H4 (Ethylene)**.

### Final Answer:
The number of female flowers can be increased by the application of **C2H4 (Ethylene)**.

---