Flowers which are pollinated by wind are

Options

A. small, brightly coloured, producing large number of pollen grains
B. small, producing large number of dry pollen grains
C. large, producing abundant nectar and pollen
D. small, producing nectar and dry pollen

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the characteristics of flowers that are pollinated by wind. This indicates we need to focus on the adaptations of such flowers for wind pollination.

2. **Analyzing the Options**:
- **Option 1**: States that these flowers are small, brightly colored, and produce a large number of pollen grains.
- **Analysis**: Wind-pollinated flowers typically do not need bright colors to attract pollinators, as they rely on wind rather than insects. Thus, this option is incorrect.

- **Option 2**: States that these flowers are small and produce a large number of dry pollen grains.
- **Analysis**: This is a characteristic of wind-pollinated flowers. They are usually small, produce a large quantity of lightweight, dry pollen that can be easily carried by the wind. This option is correct.

- **Option 3**: States that the flowers are large and produce abundant nectar.
- **Analysis**: Large flowers with abundant nectar are typically adapted for pollination by insects or birds, not by wind. Therefore, this option is incorrect.

- **Option 4**: States that the flowers are small, producing nectar and dry pollen.
- **Analysis**: While the flowers may be small, the production of nectar is associated with insect-pollinated flowers. Wind-pollinated flowers do not produce nectar as they do not need to attract pollinators. Thus, this option is also incorrect.

3. **Conclusion**: Based on the analysis of the options, the correct answer is **Option 2**: Flowers that are small and produce a large number of dry pollen grains are pollinated by wind.