Auxin takes part in

Options

A. Promotion of cell division
B. Promotion of cell enlargement
C. Promotion of fruit ripening
D. Inhibition of shoot growth.

Answer

### Step-by-Step Solution:

1. **Understanding Auxin**: Auxin is a type of plant hormone, also known as a phytohormone, that plays a crucial role in various growth processes in plants.

2. **Analyzing the Options**:
- **Option A: Promotion of Cell Division**: This function is primarily associated with another hormone called cytokinin, not auxin. Therefore, this option is incorrect.
- **Option B: Promotion of Cell Enlargement**: Auxin is known to promote cell enlargement, making this option correct.
- **Option C: Promotion of Food Ripening**: The hormone responsible for fruit ripening is ethylene, not auxin. Thus, this option is also incorrect.
- **Option D: Inhibition of Shoot Growth**: Auxin actually promotes shoot growth rather than inhibiting it. Therefore, this option is incorrect as well.

3. **Conclusion**: After analyzing all the options, the correct answer is **Option B: Promotion of Cell Enlargement**.