In which of the following, pallen grain maintains their viability of months :

Options

A. Wheat, maize
B. Rice, Wheat
C. Maize, Rice
D. Tomato, Bean

Answer

To determine which pollen grains maintain their viability for months, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Pollen Viability**: Pollen viability refers to the ability of pollen grains to germinate and fertilize ovules. Different plant species have varying durations of pollen viability.

2. **Identify Relevant Plant Families**: Some plant families are known for their pollen grains that can maintain viability for extended periods. The families mentioned are:
- Solanaceae
- Leguminaceae
- Rhoceaceae

3. **Examine the Options**: The question provides four options. We need to analyze each option to see if they belong to the families that maintain pollen viability for months.

4. **Evaluate Each Option**:
- **Option A: Wheat and Maize**: These belong to the Poaceae family and do not maintain viability for months.
- **Option B: Rice and Wheat**: Both belong to the Poaceae family, and neither maintains viability for months.
- **Option C: Maize and Rice**: Again, both belong to the Poaceae family, and neither maintains viability for months.
- **Option D: Tomato and Beans**: Tomato belongs to the Solanaceae family, and Beans belong to the Leguminaceae family. Both families are known for pollen grains that can maintain viability for months.

5. **Select the Correct Option**: Based on the analysis, the correct option is **D: Tomato and Beans**, as both belong to families that maintain pollen viability for months.

### Final Answer:
The correct answer is **D: Tomato and Beans**.

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