Which of the following is required for the formation of flowers in the plants?

Options

A. Adequate oxygen
B. Definite photoperiod
C. Adequate manure
D. Adequate water and mineral.

Explanation

To determine which factor is required for the formation of flowers in plants, let's analyze the options provided:

1. **Adequate Oxygen**: While oxygen is essential for plant respiration and overall growth, it is not a specific requirement for flower formation. Plants can produce their own oxygen through photosynthesis.

2. **Definite Photoperiod**: This is the correct option. The formation of flowers in plants is significantly influenced by the photoperiod, which refers to the duration of light and darkness a plant is exposed to. Plants can be categorized based on their photoperiodic requirements:
- **Short Day Plants**: These plants require a shorter light period to flower. If the light period exceeds a certain threshold, they will not flower.
- **Long Day Plants**: These plants need longer light periods for flowering. If the light duration is insufficient, they will not flower.
- **Day-Neutral Plants**: These plants do not have a specific light requirement for flowering and can flower regardless of the photoperiod.

3. **Adequate Manure**: While manure provides essential nutrients for overall plant growth, it does not specifically trigger flower formation.

4. **Adequate Water and Minerals**: Similar to manure, water and minerals are crucial for plant health and growth but are not directly responsible for the formation of flowers.

Based on this analysis, the correct answer is **Definite Photoperiod**.

### Steps to the Solution:
1. **Identify the Options**: Review the options given in the question.
2. **Analyze Each Option**:
- Evaluate the role of oxygen, manure, water, and minerals in plant growth and flowering.
- Focus on the significance of photoperiod in flowering.
3. **Categorize Plants by Photoperiod**: Understand how different plants respond to light duration (short day, long day, day-neutral).
4. **Select the Correct Answer**: Conclude that the definite photoperiod is essential for flower formation.